It is generally accepted that the damage recognition complex of nucleotide excision repair in Escherichia coli consists of two UvrA and one UvrB molecule, and that in the preincision complex UvrB binds to the damage as a monomer. Using scanning force microscopy, we show here that the damage recognition complex consists of two UvrA and two UvrB subunits, with the DNA wrapped around one of the UvrB monomers. Upon binding the damage and release of the UvrA subunits, UvrB remains a dimer in the preincision complex. After association with the UvrC protein, one of the UvrB monomers is released. We propose a model in which the presence of two UvrB subunits ensures damage recognition in both DNA strands. Upon binding of the UvrA(2)B(2) complex to a putative damaged site, the DNA wraps around one of the UvrB monomers, which will subsequently probe one of the DNA strands for the presence of a lesion. When no damage is found, the DNA will wrap around the second UvrB subunit, which will check the other strand for aberrations.
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http://dx.doi.org/10.1093/emboj/cdf396 | DOI Listing |
Appl Environ Microbiol
March 2024
Graduate School of Horticulture, Chiba University, Matsudo, Chiba, Japan.
sp. strain SVR uses antimonate [Sb(V)] as a terminal electron acceptor for anaerobic respiration. Here, we visualized a possible key enzyme, periplasmic Sb(V) reductase (Anr), via active staining and non-denaturing gel electrophoresis.
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July 2021
DNA:Protein Interactions Unit, School of Biochemistry, University of Bristol. Biomedical Sciences Building, University Walk, Bristol, United Kingdom.
The PcrA/UvrD helicase binds directly to RNA polymerase (RNAP) but the structural basis for this interaction and its functional significance have remained unclear. In this work, we used biochemical assays and hydrogen-deuterium exchange coupled to mass spectrometry to study the PcrA-RNAP complex. We find that PcrA binds tightly to a transcription elongation complex in a manner dependent on protein:protein interaction with the conserved PcrA C-terminal Tudor domain.
View Article and Find Full Text PDFBiochimie
March 2020
Department of Biochemistry, Indian Institute of Science, Bangalore, 560012, India. Electronic address:
The UvrB subunit is a central component of the UvrABC incision complex and plays a pivotal role in damage recognition, strand excision and repair synthesis. A conserved structural motif (the SxSx motif) present in UvrB is analogous to a similar motif (TxGx) in the helicases of superfamily 2, whose function is not fully understood. To elucidate the significance of the SxSx (Ser143-Val144-Ser145-Cys146) motif in Mycobacterium tuberculosis UvrB (MtUvrB), different variants of MtUvrB subunit were constructed and characterized.
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March 2020
Department of Biochemistry, Indian Institute of Science, Bangalore, India.
The UvrABC excinuclease plays a vital role in bacterial nucleotide excision repair. While UvrA and UvrB subunits associate to form a UvrA B complex, interaction between UvrA and UvrC has not been demonstrated or quantified in any bacterial species. Here, using Mycobacterium tuberculosis UvrA (MtUvrA), UvrB (MtUvrB) and UvrC (MtUvrC) subunits, we show that MtUvrA binds to MtUvrB and equally well to MtUvrC with submicromolar affinity.
View Article and Find Full Text PDFInt J Antimicrob Agents
April 2018
Department of Clinical Laboratory, Peking University People's Hospital, Beijing 100044, China. Electronic address:
Staphylococcus aureus small colony variants (SCVs) can cause persistent infections. However, the genomes and transcriptomes of S. aureus SCVs remain poorly understood.
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