Structural highlights
Function
[DPO3A_THEAQ] DNA polymerase III is a complex, multichain enzyme responsible for most of the replicative synthesis in bacteria. This DNA polymerase also exhibits 3' to 5' exonuclease activity. The alpha chain is the DNA polymerase (By similarity).
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 crystal structure of the catalytic alpha-subunit of the DNA polymerase III (Pol IIIalpha) holoenzyme bound to primer-template DNA and an incoming deoxy-nucleoside 5'-triphosphate has been determined at 4.6-A resolution. The polymerase interacts with the sugar-phosphate backbone of the DNA across its minor groove, which is made possible by significant movements of the thumb, finger, and beta-binding domains relative to their orientations in the unliganded polymerase structure. Additionally, the DNA and incoming nucleotide are bound to the active site of Pol IIIalpha nearly identically as they are in their complex with DNA polymerase beta, thereby proving that the eubacterial replicating polymerase, but not the eukaryotic replicating polymerase, is homologous to DNA polymerase beta. Finally, superimposing a recent structure of the clamp bound to DNA on this Pol IIIalpha complex with DNA places a loop of the beta-binding domain into the appropriate clamp cleft and supports a mechanism of polymerase switching.
Insights into the replisome from the structure of a ternary complex of the DNA polymerase III alpha-subunit.,Wing RA, Bailey S, Steitz TA J Mol Biol. 2008 Oct 17;382(4):859-69. Epub 2008 Jul 27. PMID:18691598[1]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Wing RA, Bailey S, Steitz TA. Insights into the replisome from the structure of a ternary complex of the DNA polymerase III alpha-subunit. J Mol Biol. 2008 Oct 17;382(4):859-69. Epub 2008 Jul 27. PMID:18691598 doi:10.1016/j.jmb.2008.07.058
