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
The African swine fever virus DNA polymerase X (ASFV Pol X or Pol X), the smallest known nucleotide polymerase, has recently been reported to be an extremely low fidelity polymerase that may be involved in strategic mutagenesis of the viral genome. Here we report the solution structure of Pol X. The structure, unique within the realm of nucleotide polymerases, consists of only palm and fingers subdomains. Despite the absence of a thumb subdomain, which is important for DNA binding in other polymerases, we show that Pol X binds DNA with very high affinity. Further structural analyses suggest a novel mode of DNA binding that may contribute to low fidelity synthesis. We also demonstrate that the ASFV DNA ligase is a low fidelity ligase capable of sealing a nick that contains a G-G mismatch. This supports the hypothesis of a virus-encoded, mutagenic base excision repair pathway consisting of a tandem Pol X/ligase mutator.
Solution structure of a viral DNA polymerase X and evidence for a mutagenic function.,Showalter AK, Byeon IJ, Su MI, Tsai MD Nat Struct Biol. 2001 Nov;8(11):942-6. PMID:11685239[3]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
See Also
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
- ↑ 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
