| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | ADVANCED SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
Division of Cancer Cell Research, Institute of Medical Science, University of Tokyo, Minato-ku, Tokyo, 108-8639, Japan
 |
Abstract |
|---|
 Top Abstract IntroductionResultsDiscussionExperimental proceduresReferences |
|---|
|
Introduction |
|---|
|
TopAbstractIntroductionResultsDiscussionExperimental proceduresReferences |
|---|
Several eukaryotic genes encoding homologs of MTCBP-1 have been found in DNA and protein databases. A N-terminally truncated form of MTCBP-1 is reported as Sip-L, the expression of which in non-permissive cells for hepatitis C virus (HCV) allows the virus to replicate via an as yet unknown mechanism (Yeh et al. 2001). However, it is not known yet exactly in which tissues this truncated form is expressed (Uekita et al. 2004). A rat homolog of MTCBP-1, ALP1 was recently reported to be a prostate protein that is strongly induced by androgen, and also to have proapoptotic activity (Oram et al. 2004). Like MTCBP-1, expression of ALP1 was found to be down-regulated in prostate tumors compared to normal cells. In addition, MTCBP-1 shows significant homology (28%) to a bacterial aci-reductone dioxygenase (ARD) acting in a metabolic pathway (Fig. 1A) to generate methionine from the gamma-thiomethyl group of 5'-methylthioadenosine (MTA) (Sekowska et al. 2004). ARD converts aci-reductone, an intermediate of the metabolic pathway, into two different metabolites depending on the available metal ions (Ni2+ and Fe2+) (Dai et al. 1999; Ashida et al. 2003). To date, this ARD activity has been demonstrated in two bacterial strains (Klebsiella pneumoniae (Dai et al. 1999) and Bacillus subtilis (Ashida et al. 2003)) and presumed in other organisms from the existence of homologous genes, though direct characterization of the products have not been made (Sekowska & Danchin 2002; Sekowska et al. 2004). Thus, MTCBP-1 may have ARD activity in addition to the reported functions. The three-dimensional structure of the ARD from Klebsiella pneumoniae revealed that it belongs to the recently proposed cupin superfamily which is characterized by a conserved domain called the ß-barrel fold (Pochapsky et al. 2002). MTCBP-1 and its eukaryotic homologs also show good conservation particularly in the region for the putative ß-barrel structure, and therefore, are thought to be members of the cupin superfamily. A distinguishing feature of this family is that the members have acquired diverse functions during evolution by incorporating a variety of amino acid substitutions that do not affect the ß-barrel fold (Dunwell et al. 2001). For example, the family includes isomerases, epoxidases, dioxygenases, decarboxylases, transcription factors, and centromeric proteins (Dunwell et al. 2001). Thus, it would not be surprising if eukaryotic ARD has acquired multiple functions other than the enzyme activity in the MTA cycle during the evolution from bacteria to multicellular organisms.
|
However, when we consider the functional diversity of the cupin superfamily despite the members’ sequence and structural conservation, it is particularly difficult to conclude that MTCBP-1 is the human ARD simply based on the sequence similarity. To examine whether MTCBP-1 has the ability to function in the MTA cycle, we used Saccharomyces cerevisiae to analyze the metabolic pathway by a genetic approach. First we established a yeast mutant that can utilize exogenous MTA, a precursor of the ARD substrate, as a sulfur source. Then, the YMR009w gene which potentially encodes the yeast ARD (yARD) was disrupted. The mutant cells no longer grew in the culture medium containing MTA. Growth of the cells resumed when an expression construct of the YMR009w or MTCBP-1 gene was introduced. The results indicate that Ymr009p encoded by the gene is essential to the MTA cycle and human MTCBP-1 also has the activity. Thus, the yeast YMR009w and human MTCBP-1 genes most likely encode functional eukaryotic ARDs.
|
Results |
|---|
|
TopAbstractIntroductionResultsDiscussionExperimental proceduresReferences |
|---|
A BLAST search of the databases with the human MTCBP-1 gene picked up a bacterial gene encoding ARD of Klebsiella pneumoniae, which is an aci-reductone dioxygenase of the methionine salvage pathway (MTA cycle) (Fig. 1A), and the S. cerevisiae gene YMR009w, the function of which is not known. The gene products, yeast Ymr009p and human MTCBP-1, show significant homology (23.9% and 43%, respectively) to the bacterial ARD as presented in Fig. 1B. In particular, the cupin domain that characterizes ARD is conserved well in both MTCBP-1 and Ymr009p (Fig. 1B, underlined portion). Since the 3-dimensional structure of K. pneumoniae ARD has been deposited in the Protein Data Bank (accession code 1M4O [PDB] ) (Pochapsky et al. 2002), we tried to perform modeling of MTCBP-1 and Ymr009p based on the ARD structure (Fig. 1C). The deduced structures of MTCBP-1 and Ymr009p are very similar to that of K. pneumoniae ARD at the ß-barrel fold (light blue) and flanking sequences at the amino-terminus (yellow) and carboxyl-terminus (blue). The structure of the ß-barrel fold in MTCBP-1 and Ymr009p was also similar to that of other cupin family members with different functions, oxalate oxidase (germin) (Woo et al. 2000), phosphoglucose isomerase (PGI) (Swan et al. 2003), and a transcription factor AraC (Soisson et al. 1997).
YMR009w encodes a product acting in the MTA cycle
Since YMR009w is a unique gene whose product is homologous to K. pneumoniae ARD and human MTCBP-1, we employed a genetic approach to examine whether MTCBP-1 can act as an enzyme in the eukaryotic MTA cycle. First, we tried to examine whether Ymr009p is an essential enzyme in the MTA cycle. Yeast requires a source of sulfur for cell growth and ceases proliferating under sulfur-free culture conditions (B medium) (Thomas & Surdin-Kerjan 1997). However, the cells can grow even in a sulfur-free environment if methionine or its metabolic precursor MTA is supplied as an alternative sulfur source (Thomas et al. 2000). As shown in Fig. 1A, MTA can be used as a source to generate methionine through the MTA cycle. Thus, if Ymr009p is the yeast ARD, disruption of YMR009w will abolish the ability of cells to use exogenous MTA for growth.
To disrupt the gene in yeast (Y700 strain, Table 1), the entire coding region of YMR009w was deleted and substituted with TRP1 marker gene (Fig. 2A, refer ymr009::TRP1 in Table 1). Thus, a ymr009
strain (Y700-A) lacking the gene was obtained. Disruption and substitution of the gene was confirmed by polymerase chain reaction (PCR) using specific primers as shown in Fig. 2B. The mutant cells grew well in the conventional sulfur-plus culture conditions, and no obvious phenotypic changes were observed.
|
|
strain (A2) was also established by mating ado cells and ymr009 cells.
Wild-type (Y700) and mutant strains grew normally as long as methionine and adenine were supplied in the sulfur-free B medium (Fig. 3A, + ADE), though all the strains failed to grow well in the absence of adenine source (Fig. 3A, none). Although wild-type (WT) and ymr009 cells (ymr009) could not use adenosine instead of adenine, cells with ado mutation (ado, ado/ymr009) could (Fig. 3A, + ADO). Thus, ado cells can incorporate exogenous adenosine and this ability was not affected by the disruption of YMR009w.
|
cells could grow when methionine was added to the B medium (containing adenosine) (Fig. 3B, + MET). Although ado cells could grow using MTA instead of methionine, ado/ymr009 cells failed to use MTA for growth (Fig. 3B, + MTA). Thus, the YMR009w gene appears to encode an enzyme that is essential for converting MTA to methionine (MTA cycle). MTCBP-1 complements the function of Ymr009p in yeast
To confirm that the defect in ado/ymr009 cells is caused by the lack of the YMR009w gene in the cells, an expression construct of the gene was introduced into the mutant strain. To express the gene, a hemagglutinin (HA)-tagged coding sequence was fused to the 5' end of the open reading frame for easy detection. As shown in Fig. 4A, the transformed cells recovered the ability to use exogenous MTA for growth. Considering that the YMR009w gene is unique in yeast and that the product shows significant homology to the bacterial ARD, it is most likely that the YMR009w gene encodes yeast ARD (yARD). Then, we examined whether human MTCBP-1 has similar activity to Ymr009p in yeast. Like the YMR009w-transformed cells, MTCBP1-transformed cells grew well using exogenous MTA (Fig. 4A). Thus, the human MTCBP-1 gene is thought to encode human ARD (hARD).
|
Glutamic acid in the cupin domain is indispensable for the ARD activity in yeast
The cupin domain of K. pneumoniae ARD is essential for the catalytic action and a metal ion (either Ni or Fe) held by histidine residues (H) at 96, 98 and 140 plays an essential role in the reaction. The glutamic acid residue (E) at 102 is also reported to be a ligand for Ni ion (Pochapsky et al. 2002). These histidine and glutamic acid residues are conserved well in yeast and human ARDs (Fig. 1B). To confirm that these conserved amino acid residues in yARD also play essential roles in the protein's function in the MTA cycle, we mutated glutamic acid residues in Ymr009p (Fig. 5A, E24, E45, E91 and E151) to alanine. The E/A mutants were expressed at similar levels as confirmed by Western blotting (Fig. 5B). However, all E/A mutants showed doublet bands with the upper one corresponding to the intact protein. The lower band may be an abnormally processed or degraded protein. Mutant plasmids were introduced into ado/ymr009 cells and the ability of the cells to use MTA as a sulfur source for growth was tested. Only the mutation in the cupin domain (E91A) abolished the ability to use MTA but the other mutations did not (Fig. 5C). Thus, E91 which corresponds to E102 of the bacterial ARD is indispensable for the ability to use exogenous MTA for cell growth.
|
cells (Fig. 6A). The level of expression of the mutant protein was confirmed to be comparable to that of the wild-type protein by Western blotting (Fig. 6B). The mutation abolished the ability to use exogenous MTA for cell growth (Fig. 6C).
|
Yeast ARD has an amino-terminal extension (78 amino acids) from the cupin domain (Figs 1B and 5). Such an extension also exists in ARD homologs (Fig. 1B) with less amino acid sequence conservation compared to the case of the cupin domain (Sekowska et al. 2004). Thus, we tried to evaluate the role of this region in the protein's activity as ARD in yeast. A set of deletion mutants of yARD illustrated in Fig. 7A was constructed and expressed in the ado/ymr009 cells. Deletions of more than 30 amino acids (N30, N45 and N78) abolished the ability to complement the ARD-null phenotype, even though the cupin domain remained intact (Fig. 7B). In contrast, deletions of up to 20 amino acids (N10 and N20) did not abolish the ability, but appeared to reduce it gradually.
|
cells and wild-type yARD was detected in both the cytoplasm and the nucleus consistent with the observation for hARD. The deletion of 20 amino acids (N20) significantly reduced the protein level in the cytoplasm compared to the nucleus. Further deletions completely abolished the localization of protein in the cytoplasm. Thus, the amino-terminal sequence is important for the subcellular distribution and thereby may affect the protein's ability to resume MTA-dependent cell growth. |
Discussion |
|---|
|
TopAbstractIntroductionResultsDiscussionExperimental proceduresReferences |
|---|
Sulfur is an essential environmental factor for life and cells cannot grow under sulfur-depleted conditions. MTA can be used as a sulfur source as long as it is incorporated into cells and converted to methionine through the MTA cycle. This assay was made possible by isolating a mutant that can incorporate exogenous adenosine (Thomas et al. 2000). A strain with ado mutation acquired the ability to use exogenous MTA as a source of sulfur. Disruption of the yeast ARD gene homolog, YMR009w, abolished this ability to use MTA. This is surely because of the defect in YMR009w, since the ability was restored by transformation with the expression construct of the gene. Using this yARD-null strain, it was finally demonstrated that the human MTCBP-1 gene product can act as an enzyme in the MTA cycle. Thus, eukaryotic ARD genes were functionally characterized for the first time.
Further study supported that Ymr009p and MTCBP-1 act as ARDs in the MTA cycle, because mutations of the glutamic acid residue of yeast and human ARDs that correspond to the active site of bacterial ARD inactivated their products in the MTA cycle. Bacterial ARD catalyzes different reactions using the same substrate depending on the type of metal ion bound to the active site (Dai et al. 1999; Ashida et al. 2003). One form, ARD (Ni), converts aci-reductone to 3-methylthiopropionate, carbon monoxide (CO), and formate, and the reaction is not part of the MTA cycle (off-pathway, Fig. 1A). Another form, ARD (Fe), converts the substrate to formate and a keto-acid precursor of methionine (KMTB) that is then converted to methionine (on-pathway, Fig. 1A). Structural analysis of the Ni2+-bound form of ARD from Klebsiella pneumoniae revealed that histidine and glutamic acid residues in the ß-barrel fold form the active site by folding the metal ion (Pochapsky et al. 2002). These residues are conserved in the yeast and human gene products as well (Fig. 1B). Although the structure of ARD (Ni) indicated that the conserved glutamic acid (E102) acts as a ligand for the nickel, several other conserved acidic residues including E95, E100 and D101 might serve as a ligand for the metal ion with little structural distortion (Pochapsky et al. 2002). Ligand swapping of the active site may occur depending on the bound metals and the subtle structural changes induced might be responsible for carrying out different reactions. E91 in Ymr009p corresponds to E102 in the bacterial ARD that bound to the Ni2+ ion at the active site. The mutation (E91A) in Ymr009p abolished the activity of the cells to use exogenous MTA (Fig. 5C). Although the result does not exclude the possibility that the mutation affects folding of the cupin domain, the mutated glutamic residue is surely essential for the protein to complement the defect of the gene. Although E91 corresponds to a ligand for Ni2+ in the bacterial ARD that mediates the off-pathway, the residue may also be important for the on-pathway mediated by the ARD (Fe).
The eukaryotic ARDs are thought to be multifunctional proteins (Yeh et al. 2001; Oram et al. 2004; Uekita et al. 2004). hARD binds the cytoplasmic tail of MT1-MMP and over-expression of the protein with MT1-MMP caused inhibition of the invasiveness promoted by MT1-MMP (Uekita et al. 2004). However, the binding activity was separable from the integrity of the ARD activity, because the E94A mutant which abolished the ARD activity still bound to the cytoplasmic tail peptide (data not shown) as the wild-type hARD did (Uekita et al. 2004). On the other hand, interaction between yARD and SNP1 is listed in the protein–protein interaction database in yeast (Fromont-Racine et al. 1997). We tested the yARD mutant E91A for binding to SNP1 in a yeast two-hybrid assay and found that the mutation did not affect the binding (data not shown). Although the biological role of the binding is not clear, it may guide ARD to a particular subcellular compartment.
In conclusion, we demonstrated that YMR009w encodes yeast ARD by showing that the product is required for the MTA cycle in yeast. Human MTCBP-1 which was identified by its activity to bind MT1-MMP was demonstrated to have comparable activity to yARD. We believe that this is the first clear evidence that eukaryotic ARD homologs function in the MTA cycle. However, it is still open to question whether the ARD activity is required for functions of the product in the different subcellular compartments or whether it has entirely different functions depending on the localization.
|
Experimental procedures |
|---|
|
TopAbstractIntroductionResultsDiscussionExperimental proceduresReferences |
|---|
Modeling of the 3-dimensional structure of Ymr009p and MTCBP1 was done using Discovery Studio Modeling 1.0 (Accelrys) with a standard parameter configuration, according to the manufacturer's instructions. Nuclear magnetic resonance (NMR)-derived data for ARD (Ni) from the Protein Data Bank (accession code: 1M40 [PDB] ) (Pochapsky et al. 2002) was used as a template for the modeling.
Yeast
Yeast cells of Saccharomyces cerevisiae strains were handled with standard techniques. Strains used in this study are listed in Table 1. Media used were as follows: YPAD (1% bacto-yeast extract, 2% bacto-peptone, 2% glucose, and 0.003% adenine), synthetic dropout (SD) medium (0.67% yeast nitrogen base without amino acids, 2% glucose, 0.003% adenine, and an appropriate mixture of amino acids), sporulation medium (0.1% bacto-yeast extract, 0.05% glucose, and 1% potassium acetate), and sulfur-free medium (B medium) (15 mM ammonium chloride, 6.6 mM monopotassium phosphate, 0.5 mM dipotassium phosphate, 1.7 mM sodium chloride, 0.7 mM calcium chloride, 2 mM magnesium chloride, 0.5 µg/mL boric acid, 0.04 µg/mL copper chloride (1 H2O), 0.1 µg/mL potassium iodide, 0.19 µg/mL zinc chloride, 0.05 µg/mL ferric chloride (6 H2O), 2 µg/mL calcium pantothenate, 2 µg/mL thiamine, 2 µg/mL pyridoxine, 0.02 µg/mL biotin, 20 µg/mL inositol, and 2% glucose) (Cherest & Surdin-Kerjan 1992).
Disruption of YMR009w gene
A deletion cassette was produced by polymerase chain reaction (PCR) with the primer pair 5'-CAGATCAAAAAAAACAATAACCACCAAACAAGACACTAAAAAAGGTCGTAAAAAGGTCAAGGCTGGCTTAACTATGCGGC-3' and 5'-GACTAAAAATCATTCTTGACGGGGAAGTCACCCTACGCTACTTTAAAGATATAAAGAAGTCTCCTTACGCATCTGTGCGG-3'. Yeast cells of strain Y700 were transformed with the PCR product, and selected on the SD-Trp media. Arising colonies were checked for successful recombination by colony PCR with primer pairs, a/b, b/d and c/d (a: 5'-TGACAACAAGGTTGACTCCG-3', b: 5'-GTAGTTCTGGTCCATTGGTG-3', c: 5'-TGAAGATTGAACGACCGCCC-3', d: 5'-AGTAGCAACCGCAACGTCC-3'). The isolated clone used was named as Y700-A strain (Table 1).
Isolation of a mutant able to incorporate MTA
Yeast cells of a strain < 657 (ade2) were plated on SD plates containing 1 mM adenosine instead of adenine, and cultured at 30 °C for 4 days. Spontaneously arising mutant colonies were back-crossed with parental < 657 cells 3 times, and a clone able to use adenosine as an adenine source was named as < 657-A strain (Table 1) (Thomas et al. 2000).
Production of a double mutant strain
ado cells (MATa) and ymr009 cells (MAT
) were crossed, and resultant diploid cells were plated on plates of the sporulation medium. Arising haploid colonies were verified for the ado phenotype and YMR009w disruption, and a single clone used was named as A2 strain (Table 1).
Plasmid construction
ADH1 and GAL1 promoter cassettes were produced by PCR and introduced into a yeast expression vector pRS316 (Sikorski & Hieter 1989) (kindly endowed by Dr S. Kuge, Tohoku University), yielding pRS316A and pRS316G, respectively. The open reading frames for Ymr009p (yeast) and MTCBP-1 (human) were amplified by PCR with primers containing a hemagglutinin (HA) epitope tag at their amino-termini. The PCR products were sequenced and inserted into pRS316A and pRS316G, yielding pRS316A/HA-Ymr009p, pRS316G/HA-Ymr009p, pRS316A/HA-MTCBP1, and pRS316G/HA-MTCBP1. Complementary DNAs (cDNAs) for a set of E/A mutants of HA-Ymr009p and HA-MTCBP1 were generated by PCR-based mutagenesis with each mutagenic primer pair, and cloned into pRS316G. cDNAs for a set of amino-terminally deleted mutants of Ymr009p were produced by PCR with each appropriate forward primer, and cloned into pRS316G.
Growth assay on the MTA plates
Yeast cells were precultured at 30 °C overnight in appropriate SD medium. Cells were washed twice with sterile water, and diluted in sulfur-free B medium. After 8 h culture in B media, a number of cells were spotted on to plates of B medium supplemented with MTA or methionine as a sulfur source, and cultured at 30 °C for 5 days. For ado cells every medium contained adenosine instead of adenine as an adenine source unless indicated. For the cells transformed with pRS316G, which has a GAL1 promoter, the assay plates were supplemented with galactose (2%) and raffinose (1%) instead of glucose as carbon sources, in order to activate the GAL1 promoter and induce cDNA expression.
Cell extraction
Yeast cells or transformants were cultured at 28 °C in appropriate SD medium with glucose for pSG316A transformants or with galactose/raffinose for pSG316G transformants, to an OD600 of 1.0–1.5. Cells were washed with water, and suspended in the extraction buffer (0.6 M sorbitol, and 20 mM HEPES pH 7.4) supplemented with 3 mM dithiothreitol (DTT) and protease inhibitor cocktail set III (CALBIOCHEM). Then, an equal volume of glass beads (0.5 µm in diameter) was added and the tubes were vortexed at 4 °C for 10 min. The tubes were centrifuged at 3000 r.p.m. for 5 min at 4 °C, and the supernatants were recovered, added to 2x SDS sampling buffer, boiled for 5 min and frozen at –20 °C before analysis.
Subcellular fractionation
Yeast cells cultured as above were harvested and suspended in the spheroplasting buffer (1 M sorbitol, 50 mM Tris-HCl pH 7.5, and 10 mM MgCl2) supplemented with 1 mM DTT. Zymolyase 20T (2 mg/mL, Seikagaku Kougyo) was added and incubated at 30 °C to remove cell walls. Resultant spheroplasts were washed twice with the spheroplasting buffer, and suspended in 1.5 mL/1 g cells of Ficoll buffer (18% Ficoll, 20 mM PIPES pH 6.3, 0.5 mM CaCl2, and 1 mM EDTA) supplemented with 1 mM DTT and protease inhibitor cocktail set III (CALBIOCHEM). Cells were homogenized with 60 strokes of a pestle, and unbroken cells were removed by centrifugation at 4500 r.p.m. for 5 min twice. Then, the supernatant was centrifuged at 15 000 r.p.m. for 30 min, and the pellet was recovered as the nuclear fraction, and the supernatant as the cytoplasmic fraction.
Western blotting
Yeast cell extracts or fractions were separated by 10% SDS-polyacrylamide gel electrophoresis (SDS-PAGE), and transferred to PVDF membranes (Millipore). After the blocking of nonspecific binding with 10% fat-free dry milk in Tris-buffered saline (TBS, 10 mM Tris-HCl pH 7.5, 150 mM NaCl, and 0.02% NaN3), the membranes were probed with primary antibodies, followed by horseradish peroxidase (HRP)-labeled anti-mouse IgG or anti-rabbit IgG (Amersham Biosciences). The membranes were developed with enhanced chemi-luminescent (ECL) reagent (Amersham Biosciences). Antibodies used as primary antibodies were: anti-HA (12CA5, Roche, 1 : 800), anti-PGK (22C5, Molecular Probe, 1 : 5000), and anti-RPD3 (rabbit polyclonal, Upstate Biochemistry, 1 : 1000).
|
Acknowledgements |
|---|
|
Footnotes |
|---|
aPresent address: Growth Factor Division, National Cancer Center Research Institute, Chuo-ku, Tokyo, 104-0045, Japan.
* Correspondence: E-mail: mseiki{at}ims.u-tokyo.ac.jp |
References |
|---|
|
TopAbstractIntroductionResultsDiscussionExperimental proceduresReferences |
|---|
Brinckerhoff, C.E. & Matrisian, L.M. (2002) Matrix metalloproteinases: a tail of a frog that became a prince. Nature Rev. Mol. Cell. Biol. 3, 207–214.[CrossRef][Medline]
Cherest, H. & Surdin-Kerjan, Y. (1992) Genetic analysis of a new mutation conferring cysteine auxotrophy in Saccharomyces cerevisiae: updating of the sulfur metabolism pathway. Genetics 130, 51–58.[Abstract]
Dai, Y., Wensink, P.C. & Abeles, R.H. (1999) One protein, two enzymes. J. Biol. Chem.
274, 1193–1195.
Dunwell, J.M., Culham, A., Carter, C.E., Sosa-Aguirre, C.R. & Goodenough, P.W. (2001) Evolution of functional diversity in the cupin superfamily. Trends Biochem. Sci. 26, 740–746.[CrossRef][Medline]
Egeblad, M. & Werb, Z. (2002) New functions for the matrix metalloproteinases in cancer progression. Nature Rev. Cancer 2, 161–174.[Medline]
Fromont-Racine, M., Rain, J.C. & Legrain, P. (1997) Toward a functional analysis of the yeast genome through exhaustive two-hybrid screens. Nature Genet. 16, 277–282.[CrossRef][Medline]
Oram, S., Jiang, F., Cai, X., Haleem, R., Dincer, Z. & Wang, Z. (2004) Identification and characterization of an androgen-responsive gene encoding an aci-reductone dioxygenase-like protein in the rat prostate. Endocrinology
145, 1933–1942.
Pochapsky, T.C., Pochapsky, S.S., Ju, T., Mo, H., Al-Mjeni, F. & Maroney, M.J. (2002) Modeling and experiment yields the structure of acireductone dioxygenase from Klebsiella pneumoniae. Nature Struct. Biol. 9, 966–972.[CrossRef][Medline]
Seiki, M. (2002) The cell surface: the stage for matrix metalloproteinase regulation of migration. Curr. Opin. Cell Biol. 14, 624–632.[CrossRef][Medline]
Sekowska, A. & Danchin, A. (2002) The methionine salvage pathway in Bacillus subtilis. BMC Microbiol. 2, 8.[CrossRef][Medline]
Sekowska, A., Denervaud, V., Ashida, H., et al. (2004) Bacterial variations on the methionine salvage pathway. BMC Microbiol. 4, 9.[CrossRef][Medline]
Sikorski, R.S. & Hieter, P. (1989) A system of shuttle vectors and yeast host strains designed for efficient manipulation of DNA in Saccharomyces cerevisiae. Genetics
122, 19–27.
Soisson, S.M., MacDougall-Shackleton, B., Schleif, R. & Wolberger, C. (1997) Structural basis for ligand-regulated oligomerization of AraC. Science
276, 421–425.
Swan, M.K., Solomons, J.T., Beeson, C.C., Hansen, T., Schonheit, P. & Davies, C. (2003) Structural evidence for a hydride transfer mechanism of catalysis in phosphoglucose isomerase from Pyrococcus furiosus. J. Biol. Chem.
278, 47261–47268.
Thomas, D., Becker, A. & Surdin-Kerjan, Y. (2000) Reverse methionine biosynthesis from S-adenosylmethionine in eukaryotic cells. J. Biol. Chem.
275, 40718–40724.
Thomas, D. & Surdin-Kerjan, Y. (1997) Metabolism of sulfur amino acids in Saccharomyces cerevisiae. Microbiol. Mol. Biol. Rev.
61, 503–532.
Uekita, T., Gotoh, I., Kinoshita, T., et al. (2004) Membrane-type 1 matrix metalloproteinase cytoplasmic tail-binding protein-1 is a new member of the Cupin superfamily. J. Biol. Chem.
279, 12734–12743.
Woo, E.J., Dunwell, J.M., Goodenough, P.W., Marvier, A.C. & Pickersgill, R.W. (2000) Germin is a manganese containing homohexamer with oxalate oxidase and superoxide dismutase activities. Nature Struct. Biol. 7, 1036–1040.[CrossRef][Medline]
Yeh, C.T., Lai, H.Y., Chen, T.C., Chu, C.M. & Liaw, Y.F. (2001) Identification of a hepatic factor capable of supporting hepatitis C virus replication in a nonpermissive cell line. J. Virol.
75, 11017–11024.
Received: 24 December 2004
Accepted: 8 March 2005
This article has been cited by other articles:
|
|
 |
|
  L. E. Epperson, J. C. Rose, H. V. Carey, and S. L. Martin Seasonal proteomic changes reveal molecular adaptations to preserve and replenish liver proteins during ground squirrel hibernation Am J Physiol Regulatory Integrative Comp Physiol, February 1, 2010; 298(2): R329 - R340. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 M. Costa, C. L. Borges, A. M. Bailao, G. V. Meirelles, Y. A. Mendonca, S. F. I. M. Dantas, F. P. de Faria, M. S. S. Felipe, E. E. W. I. Molinari-Madlum, M. J. S. Mendes-Giannini, et al. Transcriptome profiling of Paracoccidioides brasiliensis yeast-phase cells recovered from infected mice brings new insights into fungal response upon host interaction Microbiology, December 1, 2007; 153(12): 4194 - 4207. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 I. Gotoh, T. Uekita, and M. Seiki Regulated nucleo-cytoplasmic shuttling of human aci-reductone dioxygenase (hADI1) and its potential role in mRNA processing. Genes Cells, January 1, 2007; 12(1): 105 - 117. [Abstract] [Full Text] [PDF]
|
|
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | ADVANCED SEARCH | TABLE OF CONTENTS |
