The mutagenesis protein UmuC is a DNA polymerase activated by UmuD', RecA, and SSB and is specialized for translesion replication

Replication of DNA lesions leads to the formation of mutations. In Escherichia coli this process is regulated by the SOS stress response, and requires the mutagenesis proteins UmuC and UmuD'. Analysis of translesion replication using a recently reconstituted in vitro system (Reuven, N. B., Tome...

Full description

Saved in:
Bibliographic Details
Published in:The Journal of biological chemistry Vol. 274; no. 45; p. 31763
Main Authors: Reuven, N B, Arad, G, Maor-Shoshani, A, Livneh, Z
Format: Journal Article
Language:English
Published: United States 05.11.1999
Subjects:
Bacterial Proteins - metabolism
Base Sequence
DNA Polymerase III - metabolism
DNA Replication
DNA-Binding Proteins - metabolism
DNA-Directed DNA Polymerase
Electrophoresis, Polyacrylamide Gel
Escherichia coli
Escherichia coli Proteins
Humans
Molecular Sequence Data
Mutagenesis
Rec A Recombinases - metabolism
ISSN:0021-9258
Online Access:Get more information
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Replication of DNA lesions leads to the formation of mutations. In Escherichia coli this process is regulated by the SOS stress response, and requires the mutagenesis proteins UmuC and UmuD'. Analysis of translesion replication using a recently reconstituted in vitro system (Reuven, N. B., Tomer, G., and Livneh, Z. (1998) Mol. Cell 2, 191-199) revealed that lesion bypass occurred with a UmuC fusion protein, UmuD', RecA, and SSB in the absence of added DNA polymerase. Further analysis revealed that UmuC was a DNA polymerase (E. coli DNA polymerase V), with a weak polymerizing activity. Upon addition of UmuD', RecA, and SSB, the UmuC DNA polymerase was greatly activated, and replicated a synthetic abasic site with great efficiency (45% bypass in 6 min), 10-100-fold higher than E. coli DNA polymerases I, II, or III holoenzyme. Analysis of bypass products revealed insertion of primarily dAMP (69%), and to a lesser degree dGMP (31%) opposite the abasic site. The UmuC104 mutant protein was defective both in lesion bypass and in DNA synthesis. These results indicate that UmuC is a UmuD'-, RecA-, and SSB-activated DNA polymerase, which is specialized for lesion bypass. UmuC is a member of a new family of DNA polymerases which are specialized for lesion bypass, and include the yeast RAD30 and the human XP-V genes, encoding DNA polymerase eta.
Bibliography:ObjectType-Article-1
SourceType-Scholarly Journals-1
ObjectType-Feature-2
content type line 23
ISSN:0021-9258
DOI:10.1074/jbc.274.45.31763