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6fwk

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The crystal structure of Pol2CORE-M644G in complex with DNA and an incoming nucleotide

Structural highlights

6fwk is a 6 chain structure with sequence from Saccharomyces cerevisiae S288C and Synthetic construct. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
Method:	X-ray diffraction, Resolution 2.503Å
Ligands:	, , ,
Resources:	FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT

Function

DPOE_YEAST DNA polymerase epsilon (DNA polymerase II) participates in chromosomal DNA replication. It is required during synthesis of the leading and lagging DNA strands at the replication fork and binds at/or near replication origins and moves along DNA with the replication fork. It has 3'-5' proofreading exonuclease activity that correct errors arising during DNA replication. It is also involved in DNA synthesis during DNA repair.^[1]

Publication Abstract from PubMed

The most frequently recurring cancer-associated DNA polymerase epsilon (Pol epsilon) mutation is a P286R substitution in the exonuclease domain. While originally proposed to increase genome instability by disrupting exonucleolytic proofreading, the P286R variant was later found to be significantly more pathogenic than Pol epsilon proofreading deficiency per se. The mechanisms underlying its stronger impact remained unclear. Here we report the crystal structure of the yeast orthologue, Pol epsilon-P301R, complexed with DNA and an incoming dNTP. Structural changes in the protein are confined to the exonuclease domain, with R301 pointing towards the exonuclease site. Molecular dynamics simulations suggest that R301 interferes with DNA binding to the exonuclease site, an outcome not observed with the exonuclease-inactive Pol epsilon-D290A,E292A variant lacking the catalytic residues. These results reveal a distinct mechanism of exonuclease inactivation by the P301R substitution and a likely basis for its dramatically higher mutagenic and tumorigenic effects.

Structural consequence of the most frequently recurring cancer-associated substitution in DNA polymerase epsilon.,Parkash V, Kulkarni Y, Ter Beek J, Shcherbakova PV, Kamerlin SCL, Johansson E Nat Commun. 2019 Jan 22;10(1):373. doi: 10.1038/s41467-018-08114-9. PMID:30670696^[2]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

References

↑ Shimizu K, Hashimoto K, Kirchner JM, Nakai W, Nishikawa H, Resnick MA, Sugino A. Fidelity of DNA polymerase epsilon holoenzyme from budding yeast Saccharomyces cerevisiae. J Biol Chem. 2002 Oct 4;277(40):37422-9. Epub 2002 Jul 17. PMID:12124389 doi:http://dx.doi.org/10.1074/jbc.M204476200
↑ Parkash V, Kulkarni Y, Ter Beek J, Shcherbakova PV, Kamerlin SCL, Johansson E. Structural consequence of the most frequently recurring cancer-associated substitution in DNA polymerase ε. Nat Commun. 2019 Jan 22;10(1):373. PMID:30670696 doi:10.1038/s41467-018-08114-9