Structural highlights
3gik is a 3 chain structure with sequence from Sulso. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
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| Ligands: | , |
| NonStd Res: | , |
| Related: | |
| Gene: | dbh, dpo4, SSO2448 (SULSO) |
| Activity: | DNA-directed DNA polymerase, with EC number 2.7.7.7 |
| Resources: | FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT |
Function
[DPO4_SULSO] Poorly processive, error-prone DNA polymerase involved in untargeted mutagenesis. Copies undamaged DNA at stalled replication forks, which arise in vivo from mismatched or misaligned primer ends. These misaligned primers can be extended by PolIV. Exhibits no 3'-5' exonuclease (proofreading) activity. It is involved in translesional synthesis.[HAMAP-Rule:MF_01113]
Evolutionary Conservation
Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf.
Publication Abstract from PubMed
7,8-Dihydro-8-oxoguanine (oxoG), the predominant oxidative DNA damage lesion, is processed differently by high-fidelity and Y-family lesion bypass polymerases. Although high-fidelity polymerases extend predominantly from an A base opposite an oxoG, the Y-family polymerases Dpo4 and human Pol eta preferentially extend from the oxoG*C base pair. We have determined crystal structures of extension Dpo4 ternary complexes with oxoG opposite C, A, G, or T and the next nascent base pair. We demonstrate that neither template backbone nor the architecture of the active site is perturbed by the oxoG(anti)*C and oxoG*A pairs. However, the latter manifest conformational heterogeneity, adopting both oxoG(syn)*A(anti) and oxoG(anti)*A(syn) alignment. Hence, the observed reduced primer extension from the dynamically flexible 3'-terminal primer base A is explained. Because of homology between Dpo4 and Pol eta, such a dynamic screening mechanism might be utilized by Dpo4 and Pol eta to regulate error-free versus error-prone bypass of oxoG and other lesions.
Impact of conformational heterogeneity of OxoG lesions and their pairing partners on bypass fidelity by Y family polymerases.,Rechkoblit O, Malinina L, Cheng Y, Geacintov NE, Broyde S, Patel DJ Structure. 2009 May 13;17(5):725-36. PMID:19446528[1]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Rechkoblit O, Malinina L, Cheng Y, Geacintov NE, Broyde S, Patel DJ. Impact of conformational heterogeneity of OxoG lesions and their pairing partners on bypass fidelity by Y family polymerases. Structure. 2009 May 13;17(5):725-36. PMID:19446528 doi:10.1016/j.str.2009.03.011
