Journal
MOLECULAR AND CELLULAR BIOLOGY
Volume 22, Issue 3, Pages 784-791Publisher
AMER SOC MICROBIOLOGY
DOI: 10.1128/MCB.22.3.784-791.2002
Keywords
-
Categories
Funding
- NIGMS NIH HHS [GM19261, GM38559] Funding Source: Medline
Ask authors/readers for more resources
Humans have three DNA polymerases, Poleta, Polkappa, and Poliota, which are able to promote replication through DNA lesions. However, the mechanism by which these DNA polymerases are targeted to the replication machinery stalled at a lesion site has remained unknown. Here, we provide evidence for the physical interaction of human Polkappa (hPolkappa) with proliferating cell nuclear antigen (PCNA) and show that PCNA, replication factor C (RFC), and replication protein A (RPA) act cooperatively to stimulate the DNA synthesis activity of hPolkappa. The processivity of hPolkappa, however, is not significantly increased in the presence of these protein factors. The efficiency (V-max/K-m) of correct nucleotide incorporation by hPolkappa is enhanced similar to50- to 200-fold in the presence of PCNA, RFC, and RPA, and this increase in efficiency is achieved by a reduction in the apparent K-m for the nucleotide. Although in the presence of these protein factors, the efficiency of the insertion of an A nucleotide opposite an abasic site is increased similar to40-fold, this reaction still remains quite inefficient; thus, it is unlikely that hPolkappa would bypass an abasic site by inserting a nucleotide opposite the site.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available