Structural highlights
Function
[DPOLX_ASFB7] Error-prone polymerase lacking a proofreading 3'-5' exonuclease which plays a role in viral DNA repair. Specifically binds intermediates in the single-nucleotide base-excision repair process. Also catalyzes DNA polymerization with low nucleotide-insertion fidelity. Together with the viral DNA ligase, fills the single nucleotide gaps generated by the AP endonuclease.[1] [2]
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
DNA polymerase X (Pol X) from the African swine fever virus (ASFV) specifically binds intermediates in the single-nucleotide base-excision repair process, an activity indicative of repair function. In addition, Pol X catalyzes DNA polymerization with low nucleotide-insertion fidelity. The structural mechanisms by which DNA polymerases confer high or low fidelity in DNA polymerization remain to be elucidated. The three-dimensional structure of Pol X has been determined. Unlike other DNA polymerases, Pol X is formed from only a palm and a C-terminal subdomain. Pol X has a novel palm subdomain fold, containing a positively charged helix at the DNA binding surface. Purine deoxynucleoside triphosphate (dNTP) substrates bind between the palm and C-terminal subdomain, at a dNTP-binding helix, and induce a unique conformation in Pol X. The purine dNTP-bound conformation and high binding affinity for dGTP-Mg(2+) of Pol X may contribute to its low fidelity.
Solution structure of a viral DNA repair polymerase.,Maciejewski MW, Shin R, Pan B, Marintchev A, Denninger A, Mullen MA, Chen K, Gryk MR, Mullen GP Nat Struct Biol. 2001 Nov;8(11):936-41. PMID:11685238[3]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Garcia-Escudero R, Garcia-Diaz M, Salas ML, Blanco L, Salas J. DNA polymerase X of African swine fever virus: insertion fidelity on gapped DNA substrates and AP lyase activity support a role in base excision repair of viral DNA. J Mol Biol. 2003 Mar 7;326(5):1403-12. PMID:12595253
- ↑ Showalter AK, Byeon IJ, Su MI, Tsai MD. Solution structure of a viral DNA polymerase X and evidence for a mutagenic function. Nat Struct Biol. 2001 Nov;8(11):942-6. PMID:11685239 doi:10.1038/nsb1101-942
- ↑ Maciejewski MW, Shin R, Pan B, Marintchev A, Denninger A, Mullen MA, Chen K, Gryk MR, Mullen GP. Solution structure of a viral DNA repair polymerase. Nat Struct Biol. 2001 Nov;8(11):936-41. PMID:11685238 doi:10.1038/nsb1101-936
