7KTK

DNA Polymerase Mu (K438D), 8-oxodGTP:Ct Ground State Ternary Complex, 50 mM Mg2+ (90min)

Summary for 7KTK

• Entry DOI: 10.2210/pdb7ktk/pdb
• Descriptor: DNA-directed DNA/RNA polymerase mu, DNA (5'-D(*CP*GP*GP*CP*CP*TP*AP*CP*G)-3'), DNA (5'-D(*CP*GP*TP*A)-3'), ... (10 entities in total)
• Functional Keywords: time-lapse crystallography, oxidized nucleotide insertion, dna polymerase mu, double strand break repair, replication
• Biological source: Homo sapiens (Human); More
• Total number of polymer chains: 4
• Total formula weight: 46655.61

Authors

Jamsen, J.A.,Wilson, S.H. (deposition date: 2020-11-24, release date: 2022-05-11, Last modification date: 2023-10-18)

Primary citation

Jamsen, J.A.,Sassa, A.,Shock, D.D.,Beard, W.A.,Wilson, S.H.
Watching a double strand break repair polymerase insert a pro-mutagenic oxidized nucleotide.
Nat Commun, 12:2059-2059, 2021

PubMed Abstract: Oxidized dGTP (8-oxo-7,8-dihydro-2´-deoxyguanosine triphosphate, 8-oxodGTP) insertion by DNA polymerases strongly promotes cancer and human disease. How DNA polymerases discriminate against oxidized and undamaged nucleotides, especially in error-prone double strand break (DSB) repair, is poorly understood. High-resolution time-lapse X-ray crystallography snapshots of DSB repair polymerase μ undergoing DNA synthesis reveal that a third active site metal promotes insertion of oxidized and undamaged dGTP in the canonical anti-conformation opposite template cytosine. The product metal bridged O8 with product oxygens, and was not observed in the syn-conformation opposite template adenine (A). Rotation of A into the syn-conformation enabled undamaged dGTP misinsertion. Exploiting metal and substrate dynamics in a rigid active site allows 8-oxodGTP to circumvent polymerase fidelity safeguards to promote pro-mutagenic double strand break repair.

PubMed: 33824325
DOI: 10.1038/s41467-021-21354-6

Experimental method

X-RAY DIFFRACTION (1.419 Å)