Multipartite control of the DNA translocase, Mfd.
ATP-dependent nucleic acid helicases and translocases play essential roles in many aspects of DNA and RNA biology. In order to ensure that these proteins act only in specific contexts, their activity is often regulated by intramolecular contacts and interaction with partner proteins. We have studied the bacterial Mfd protein, which is an ATP-dependent DNA translocase that relocates or displaces transcription ECs in a variety of cellular contexts. When bound to RNAP, Mfd exhibits robust ATPase and DNA translocase activities, but when released from its substrate these activities are repressed by autoinhibitory interdomain contacts. In this work, we have identified an interface within the Mfd protein that is important for regulating the activity of the protein, and whose disruption permits Mfd to act indiscriminately at transcription complexes that lack the usual determinants of Mfd specificity. Our results indicate that regulation of Mfd occurs through multiple nodes, and that activation of Mfd may be a multi-stage process.
DNA-protein interactions unit, School of Biochemistry, University of Bristol, Bristol BS8 1TD, UK.
Abigail J
AJ
Smith
Christian
C
Pernstich
Nigel J
NJ
Savery
D000251:Adenosine Triphosphatases / Q000737:chemistry / Q000378:metabolism; D001426:Bacterial Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D004247:DNA / Q000378:metabolism*; D009154:Mutation; D017434:Protein Structure, Tertiary; D059748:Proteolysis; D014157:Transcription Factors / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D014158:Transcription, Genetic
D001426:Bacterial Proteins; D014157:Transcription Factors; C072103:transcription repair coupling factor protein, Bacteria; D004247:DNA; D000251:Adenosine Triphosphatases