5DA7

monomeric PCNA bound to a small protein inhibitor

Summary for 5DA7

• Entry DOI: 10.2210/pdb5da7/pdb
• Related: 3LX1 5DAI
• Descriptor: DNA polymerase sliding clamp 1, Proliferating cell nuclear antigen, Thermococcales inhibitor of PCNA, SULFATE ION (3 entities in total)
• Functional Keywords: complex, inhibitor, dna binding protein-inhibitor complex, dna binding protein/inhibitor
• Biological source: Thermococcus kodakarensis (strain ATCC BAA-918 / JCM 12380 / KOD1); More
• Total number of polymer chains: 4
• Total formula weight: 75187.65

Authors

Ladner, J.E.,Altieri, A.S.,Kelman, Z. (deposition date: 2015-08-19, release date: 2016-05-11, Last modification date: 2023-09-27)

Primary citation

Altieri, A.S.,Ladner, J.E.,Li, Z.,Robinson, H.,Sallman, Z.F.,Marino, J.P.,Kelman, Z.
A small protein inhibits proliferating cell nuclear antigen by breaking the DNA clamp.
Nucleic Acids Res., 44:6232-6241, 2016

PubMed Abstract: Proliferating cell nuclear antigen (PCNA) forms a trimeric ring that encircles duplex DNA and acts as an anchor for a number of proteins involved in DNA metabolic processes. PCNA has two structurally similar domains (I and II) linked by a long loop (inter-domain connector loop, IDCL) on the outside of each monomer of the trimeric structure that makes up the DNA clamp. All proteins that bind to PCNA do so via a PCNA-interacting peptide (PIP) motif that binds near the IDCL. A small protein, called TIP, binds to PCNA and inhibits PCNA-dependent activities although it does not contain a canonical PIP motif. The X-ray crystal structure of TIP bound to PCNA reveals that TIP binds to the canonical PIP interaction site, but also extends beyond it through a helix that relocates the IDCL. TIP alters the relationship between domains I and II within the PCNA monomer such that the trimeric ring structure is broken, while the individual domains largely retain their native structure. Small angle X-ray scattering (SAXS) confirms the disruption of the PCNA trimer upon addition of the TIP protein in solution and together with the X-ray crystal data, provides a structural basis for the mechanism of PCNA inhibition by TIP.

PubMed: 27141962
DOI: 10.1093/nar/gkw351

Experimental method

X-RAY DIFFRACTION (2.802 Å)