Interaction of Escherichia coli RNA polymerase with the ribosomal protein S1 and the Sm-like ATPase Hfq.
We report evidence that ribosomal protein S1 and nucleic acid-binding protein Hfq copurify in molar ratios with RNA polymerase (RNAP). Purified S1 associates independently with RNAP, and Hfq binding to polymerase occurs in the presence of S1. Looking for a functional role of the RNAP-S1-Hfq association, we studied the effects of S1 and Hfq on transcription and coupled transcription-translation. S1 was capable of significant stimulation of the RNAP transcriptional activity from a number of promoters; the stimulatory effect was observed on linear as well as supercoiled DNA templates. In addition, we present biochemical and genetic evidence of ATPase activity associated with the Sm-like hexameric nucleic acid-binding protein Hfq. The limited sequence homology between Hfq and known ATP-utilizing enzymes suggests a new class of ATPases.
Sukhodolets
Maxim V
MV
Laboratory of Molecular Biology, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892, USA. soukhodm@dc37a.nci.nih.gov
Garges
Susan
S
D000251:Adenosine Triphosphatases / Q000378:metabolism*; D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D015153:Blotting, Western; D012321:DNA-Directed RNA Polymerases / Q000235:genetics / Q000378:metabolism*; D004926:Escherichia coli / Q000201:enzymology* / Q000378:metabolism; D035001:Host Factor 1 Protein / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D010957:Plasmids; D011485:Protein Binding; D014176:Protein Biosynthesis; D012329:RNA, Bacterial / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics* / Q000378:metabolism; D011994:Recombinant Proteins / Q000302:isolation & purification / Q000378:metabolism; D017411:Ribonucleoproteins, Small Nuclear / Q000235:genetics / Q000378:metabolism; D012269:Ribosomal Proteins / Q000235:genetics / Q000378:metabolism*; D012270:Ribosomes / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D012808:Sigma Factor / Q000378:metabolism; D014158:Transcription, Genetic
D001426:Bacterial Proteins; D035001:Host Factor 1 Protein; D012329:RNA, Bacterial; D012333:RNA, Messenger; D011994:Recombinant Proteins; D017411:Ribonucleoproteins, Small Nuclear; D012269:Ribosomal Proteins; D012808:Sigma Factor; C015494:ribosomal protein S1; D012321:DNA-Directed RNA Polymerases; D000251:Adenosine Triphosphatases