8THW
Cac1 PIP motif bound to PCNA
Summary for 8THW
| Entry DOI | 10.2210/pdb8thw/pdb |
| Descriptor | Proliferating cell nuclear antigen,Chromatin assembly factor 1 subunit p90 (1 entity in total) |
| Functional Keywords | sliding clamp, histone chaperone, replication-coupled nucleosome assembly, chromatin assembly, gene silencing, protein complex, pip, protein binding |
| Biological source | Saccharomyces cerevisiae S288C More |
| Total number of polymer chains | 3 |
| Total formula weight | 97166.62 |
| Authors | |
| Primary citation | Orndorff, K.S.,Veltri, E.J.,Hoitsma, N.M.,Williams, I.L.,Hall, I.,Jaworski, G.E.,Majeres, G.E.,Kallepalli, S.,Vito, A.F.,Struble, L.R.,Borgstahl, G.E.O.,Dieckman, L.M. Structural Basis for the Interaction Between Yeast Chromatin Assembly Factor 1 and Proliferating Cell Nuclear Antigen. J.Mol.Biol., 436:168695-168695, 2024 Cited by PubMed Abstract: Proliferating cell nuclear antigen (PCNA), the homotrimeric eukaryotic sliding clamp protein, recruits and coordinates the activities of a multitude of proteins that function on DNA at the replication fork. Chromatin assembly factor 1 (CAF-1), one such protein, is a histone chaperone that deposits histone proteins onto DNA immediately following replication. The interaction between CAF-1 and PCNA is essential for proper nucleosome assembly at silenced genomic regions. Most proteins that bind PCNA contain a PCNA-interacting peptide (PIP) motif, a conserved motif containing only eight amino acids. Precisely how PCNA is able to discriminate between binding partners at the replication fork using only these small motifs remains unclear. Yeast CAF-1 contains a PIP motif on its largest subunit, Cac1. We solved the crystal structure of the PIP motif of CAF-1 bound to PCNA using a new strategy to produce stoichiometric quantities of one PIP motif bound to each monomer of PCNA. The PIP motif of CAF-1 binds to the hydrophobic pocket on the front face of PCNA in a similar manner to most known PIP-PCNA interactions. However, several amino acids immediately flanking either side of the PIP motif bind the IDCL or C-terminus of PCNA, as observed for only a couple other known PIP-PCNA interactions. Furthermore, mutational analysis suggests positively charged amino acids in these flanking regions are responsible for the low micromolar affinity of CAF-1 for PCNA, whereas the presence of a negative charge upstream of the PIP prevents a more robust interaction with PCNA. These results provide additional evidence that positive charges within PIP-flanking regions of PCNA-interacting proteins are crucial for specificity and affinity of their recruitment to PCNA at the replication fork. PubMed: 38969056DOI: 10.1016/j.jmb.2024.168695 PDB entries with the same primary citation |
| Experimental method | X-RAY DIFFRACTION (2.6 Å) |
Structure validation
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