Premium
Regulation of DNA replication and repair proteins through interaction with the front side of proliferating cell nuclear antigen
Author(s) -
Jónsson Zophonías O,
Hindges Robert,
Hübscher Ulrich
Publication year - 1998
Publication title -
the embo journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 7.484
H-Index - 392
eISSN - 1460-2075
pISSN - 0261-4189
DOI - 10.1093/emboj/17.8.2412
Subject(s) - proliferating cell nuclear antigen , dna replication , library science , biology , dna , biochemistry , computer science
The DNA polymerase accessory factor proliferating cell nuclear antigen (PCNA) has been caught in interaction with an ever increasing number of proteins. To characterize the sites and functions of some of these interactions, we constructed four mutants of human PCNA and analysed them in a variety of assays. By targeting loops on the surface of the PCNA trimer and changing three or four residues at a time to alanine, we found that a region including part of the domain‐connecting loop of PCNA and loops on one face of the trimer, close to the C‐termini, is involved in binding to all of the following proteins: DNA polymerase δ, replication factor C, the flap endonuclease Fen1, the cyclin dependent kinase inhibitor p21 and DNA ligase I. An inhibition of DNA ligation caused by the interaction of PCNA with DNA ligase I was found, and we show that DNA ligase I and Fen1 can inhibit DNA synthesis by DNA polymerase δ/PCNA. We demonstrate that PCNA must be located below a 5′ flap on a forked template to stimulate Fen1 activity, and considering the interacting region on PCNA for Fen1, this suggests an orientation for PCNA during DNA replication with the C‐termini facing forwards, in the direction of DNA synthesis.