Abstract
Transcription and DNA repair are coupled in E. coli by the Mfd protein, which dissociates transcription elongation complexes blocked at nonpairing lesions and mediates recruitment of DNA repair proteins. We show that Mfd influences the elongation state of RNA polymerase (RNAP); transcription complexes that have reverse translocated into the backtracked position, a potentially important intermediate in RNA proofreading and repair, are restored to the forward position by the activity of Mfd, and arrested complexes are rescued into productive elongation. Mfd may act through a translocase activity that rewinds upstream DNA, leading either to translocation or to release of RNA polymerase when the enzyme active site cannot continue elongation.
Publication types
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Research Support, U.S. Gov't, P.H.S.
MeSH terms
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Bacterial Proteins / metabolism*
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Base Sequence
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Binding Sites
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DNA Repair
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DNA-Directed RNA Polymerases / metabolism
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Dose-Response Relationship, Drug
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Escherichia coli / metabolism*
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Exodeoxyribonucleases / metabolism
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Models, Molecular
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Molecular Sequence Data
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Plasmids / metabolism
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Protein Binding
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Protein Transport
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RNA / metabolism
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RNA, Messenger / metabolism
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Sequence Homology, Nucleic Acid
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Sigma Factor / metabolism
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Transcription Factors / metabolism*
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Transcription, Genetic*
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Two-Hybrid System Techniques
Substances
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Bacterial Proteins
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RNA, Messenger
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Sigma Factor
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Transcription Factors
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transcription repair coupling factor protein, Bacteria
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RNA
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RNA polymerase sigma 70
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DNA-Directed RNA Polymerases
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Exodeoxyribonucleases
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exodeoxyribonuclease III