8vx4
Human OGG1 bound to a 35-bp DNA with an 8-oxoG in the middle
Structural highlights
DiseaseOGG1_HUMAN Defects in OGG1 may be a cause of renal cell carcinoma (RCC) [MIM:144700. It is a heterogeneous group of sporadic or hereditary carcinoma derived from cells of the proximal renal tubular epithelium. It is subclassified into clear cell renal carcinoma (non-papillary carcinoma), papillary renal cell carcinoma, chromophobe renal cell carcinoma, collecting duct carcinoma with medullary carcinoma of the kidney, and unclassified renal cell carcinoma. FunctionOGG1_HUMAN DNA repair enzyme that incises DNA at 8-oxoG residues. Excises 7,8-dihydro-8-oxoguanine and 2,6-diamino-4-hydroxy-5-N-methylformamidopyrimidine (FAPY) from damaged DNA. Has a beta-lyase activity that nicks DNA 3' to the lesion. Publication Abstract from PubMedThe human glycosylase OGG1 extrudes and excises the oxidized DNA base 8-oxoguanine (8-oxoG) to initiate base excision repair and plays important roles in many pathological conditions such as cancer, inflammation, and neurodegenerative diseases. Previous structural studies have used a truncated protein and short linear DNA, so it has been unclear how full-length OGG1 operates on longer DNA or on nucleosomes. Here we report cryo-EM structures of human OGG1 bound to a 35-bp long DNA containing an 8-oxoG within an unmethylated Cp-8-oxoG dinucleotide as well as to a nucleosome with an 8-oxoG at super-helical location (SHL)-5. The 8-oxoG in the linear DNA is flipped out by OGG1, consistent with previous crystallographic findings with a 15-bp DNA. OGG1 preferentially binds near dsDNA ends at the nucleosomal entry/exit sites. Such preference may underlie the enzyme's function in DNA double-strand break repair. Unexpectedly, we find that OGG1 bends the nucleosomal entry DNA, flips an undamaged guanine, and binds to internal nucleosomal DNA sites such as SHL-5 and SHL+6. We suggest that the DNA base search mechanism by OGG1 may be chromatin context-dependent and that OGG1 may partner with chromatin remodelers to excise 8-oxoG at the nucleosomal internal sites. Human 8-oxoguanine glycosylase OGG1 binds nucleosome at the dsDNA ends and the super-helical locations.,You Q, Feng X, Cai Y, Baylin SB, Li H Commun Biol. 2024 Sep 28;7(1):1202. doi: 10.1038/s42003-024-06919-7. PMID:39341999[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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