HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE ADVANCED SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Similar articles in this journal Alert me to new issues of the journal Download to citation manager Google Scholar Articles by Phadtare, S. Articles by Severinov, K. PubMed Articles by Phadtare, S. Articles by Severinov, K.

¹ Department of Biochemistry, Robert Wood Johnson Medical School, 675 Hoes Lane, Piscataway, New Jersey 08854, USA
² Waksman Institute, Department of Biochemistry and Molecular Biology, Rutgers, The State University of New Jersey, 190 Frelinghuysen Road, Piscataway, New Jersey 08854, USA
³ Institutes of Molecular Genetics and Gene Biology, Russian Academy of Sciences, Moscow, Russia

In Escherichia coli, temperature downshift elicits cold shock response, which is characterized by induction of cold shock proteins. CspA, the major cold shock protein of E. coli, helps cells to acclimatize to low temperature by melting the secondary structures in nucleic acids and acting as a transcription antiterminator. CspA and its homologues contain the cold shock domain and belong to the oligomer binding protein family, which also includes S1 domain proteins such as IF1. Structural similarity between IF1 and CspA homologues suggested a functional overlap between these proteins. Indeed IF1 can melt secondary structures in RNA and acts as transcription antiterminator in vivo and in vitro. Here, we show that in spite of having these critical activities, IF1 does not complement cold-sensitivity of a csp quadruple deletion strain. DNA microarray analysis shows that overproduction of IF1 and Csp leads to changes in expression of different sets of genes. Importantly, several genes which were previously shown to require Csp proteins for their expression at low temperature did not respond to IF1. Moreover, in vitro, we show that a transcription terminator responsive to Csp does not respond to IF1. Our results suggest that Csp proteins and IF1 have different sets of target genes as they may be suppressing the function of different types of transcription termination elements in specific genes.

^* phadtasa{at}umdnj.edu