2b2n
From Proteopedia
Structure of transcription-repair coupling factor
Structural highlights
Function[MFD_ECOLI] Couples transcription and DNA repair by recognizing RNA polymerase (RNAP) stalled at DNA lesions. Mediates ATP-dependent release of RNAP and its truncated transcript from the DNA, and recruitment of nucleotide excision repair machinery to the damaged site. Can also dissociate RNAP that is blocked by low concentration of nucleoside triphosphates or by physical obstruction, such as bound proteins. In addition, can rescue arrested complexes by promoting forward translocation. Has ATPase activity, which is required for removal of stalled RNAP, but seems to lack helicase activity. May act through a translocase activity that rewinds upstream DNA, leading either to translocation or to release of RNAP when the enzyme active site can not continue elongation.[1] [2] [3] [4] [5] Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedThe transcription repair coupling factor Mfd removes stalled RNA polymerase from DNA lesions and links transcription to UvrABC-dependent nucleotide excision repair in prokaryotes. We report the 2.1A crystal structure of the UvrA-binding N terminus (residues 1-333) of Escherichia coli Mfd (Mfd-N). Remarkably, Mfd-N reveals a fold that resembles the three N-terminal domains of the repair enzyme UvrB. Domain 1A of Mfd adopts a typical RecA fold, domain 1B matches the damage-binding domain of the UvrB, and domain 2 highly resembles the implicated UvrA-binding domain of UvrB. However, Mfd apparently lacks a functional ATP-binding site and does not contain the DNA damage-binding motifs of UvrB. Thus, our results suggest that Mfd might form a UvrA recruitment factor at stalled transcription complexes that architecturally but not catalytically resembles UvrB. Structural basis for transcription-coupled repair: the N terminus of Mfd resembles UvrB with degenerate ATPase motifs.,Assenmacher N, Wenig K, Lammens A, Hopfner KP J Mol Biol. 2006 Jan 27;355(4):675-83. Epub 2005 Nov 8. PMID:16309703[6] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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