Myxococcus xanthus translesion DNA synthesis protein ImuA is an ATPase enhanced by DNA.

Autor: Lichimo K; Biochemistry and Biomedical Sciences, McMaster University, Hamilton, Ontario, Canada.; Michael G. DeGroote Institute for Infectious Disease Research, McMaster University, Hamilton, Ontario, Canada., Sowa DJ; Biochemistry and Biomedical Sciences, McMaster University, Hamilton, Ontario, Canada.; Michael G. DeGroote Institute for Infectious Disease Research, McMaster University, Hamilton, Ontario, Canada., Tetenych A; Biochemistry and Biomedical Sciences, McMaster University, Hamilton, Ontario, Canada.; Michael G. DeGroote Institute for Infectious Disease Research, McMaster University, Hamilton, Ontario, Canada., Warner MM; Biochemistry and Biomedical Sciences, McMaster University, Hamilton, Ontario, Canada.; Michael G. DeGroote Institute for Infectious Disease Research, McMaster University, Hamilton, Ontario, Canada., Doubleday C; Biochemistry and Biomedical Sciences, McMaster University, Hamilton, Ontario, Canada.; Michael G. DeGroote Institute for Infectious Disease Research, McMaster University, Hamilton, Ontario, Canada., Dev HS; Biochemistry and Biomedical Sciences, McMaster University, Hamilton, Ontario, Canada.; Michael G. DeGroote Institute for Infectious Disease Research, McMaster University, Hamilton, Ontario, Canada., Luck C; Biochemistry and Biomedical Sciences, McMaster University, Hamilton, Ontario, Canada.; Michael G. DeGroote Institute for Infectious Disease Research, McMaster University, Hamilton, Ontario, Canada., Andres SN; Biochemistry and Biomedical Sciences, McMaster University, Hamilton, Ontario, Canada.; Michael G. DeGroote Institute for Infectious Disease Research, McMaster University, Hamilton, Ontario, Canada.
Jazyk: angličtina
Zdroj: Protein science : a publication of the Protein Society [Protein Sci] 2024 May; Vol. 33 (5), pp. e4981.
DOI: 10.1002/pro.4981
Abstrakt: Translesion DNA synthesis pathways are necessary to ensure bacterial replication in the presence of DNA damage. Translesion DNA synthesis carried out by the PolV mutasome is well-studied in Escherichia coli, but ~one third of bacteria use a functionally homologous protein complex, consisting of ImuA, ImuB, and ImuC (also called DnaE2). Numerous in vivo studies have shown that all three proteins are required for translesion DNA synthesis and that ImuC is the error-prone polymerase, but the roles of ImuA and ImuB are unclear. Here we carry out biochemical characterization of ImuA and a truncation of ImuB from Myxococcus xanthus. We find that ImuA is an ATPase, with ATPase activity enhanced in the presence of DNA. The ATPase activity is likely regulated by the C-terminus, as loss of the ImuA C-terminus results in DNA-independent ATP hydrolysis. We also find that ImuA binds a variety of DNA substrates, with DNA binding affinity affected by the addition of ADP or adenylyl-imidodiphosphate. An ImuB truncation also binds DNA, with lower affinity than ImuA. In the absence of DNA, ImuA directly binds ImuB with moderate affinity. Finally, we show that ImuA and ImuB self-interact, but that ImuA is predominantly a monomer, while truncated ImuB is a trimer in vitro. Together, with our findings and the current literature in the field, we suggest a model for translesion DNA synthesis, where a trimeric ImuB would provide sufficient binding sites for DNA, the β-clamp, ImuC, and ImuA, and where ImuA ATPase activity may regulate assembly and disassembly of the translesion DNA synthesis complex.
(© 2024 The Authors. Protein Science published by Wiley Periodicals LLC on behalf of The Protein Society.)
Databáze: MEDLINE
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