Structural and Thermodynamic Analysis of Human PCNA with Peptides Derived from DNA Polymerase-delta p66 Subunit and Flap Endonuclease-1.Bruning, J.B., Shamoo, Y.
(2004) Structure 12: 2209-2219
- PubMed: 15576034
- DOI: https://doi.org/10.1016/j.str.2004.09.018
- Primary Citation of Related Structures:
- PubMed Abstract:
Human Proliferating Cellular Nuclear Antigen (hPCNA), a member of the sliding clamp family of proteins, makes specific protein-protein interactions with DNA replication and repair proteins through a small peptide motif termed the PCNA-interacting protein, or PIP-box. We solved the structure of hPCNA bound to PIP-box-containing peptides from the p66 subunit of the human replicative DNA polymerase-delta (452-466) at 2.6 A and of the flap endonuclease (FEN1) (331-350) at 1.85 A resolution. Both structures demonstrate that the pol-delta p66 and FEN1 peptides interact with hPCNA at the same site shown to bind the cdk-inhibitor p21(CIP1). Binding studies indicate that peptides from the p66 subunit of the pol-delta holoenzyme and FEN1 bind hPCNA from 189- to 725-fold less tightly than those of p21. Thus, the PIP-box and flanking regions provide a small docking peptide whose affinities can be readily adjusted in accord with biological necessity to mediate the binding of DNA replication and repair proteins to hPCNA.
Department of Biochemistry and Cell Biology, Rice University, 6100 South Main Street, MS140, Houston, TX 77005, USA.