Full-length M. smegmatis Pol1Full-length M. smegmatis Pol1

Structural highlights

6vde is a 2 chain structure with sequence from Mycolicibacterium smegmatis. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
Method:X-ray diffraction, Resolution 2.713Å
Ligands:
Resources:FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT

Function

A0QYZ2_MYCS2 In addition to polymerase activity, this DNA polymerase exhibits 5'-3' exonuclease activity.[RuleBase:RU004460]

Publication Abstract from PubMed

Mycobacterial Pol1 is a bifunctional enzyme composed of an N-terminal DNA flap endonuclease/5' exonuclease domain (FEN/EXO) and a C-terminal DNA polymerase domain (POL). Here we document additional functions of Pol1: FEN activity on the flap RNA strand of an RNA:DNA hybrid and reverse transcriptase activity on a DNA-primed RNA template. We report crystal structures of the POL domain, as apoenzyme and as ternary complex with 3'-dideoxy-terminated DNA primer-template and dNTP. The thumb, palm, and fingers subdomains of POL form an extensive interface with the primer-template and the triphosphate of the incoming dNTP. Progression from an open conformation of the apoenzyme to a nearly closed conformation of the ternary complex entails a disordered-to-ordered transition of several segments of the thumb and fingers modules and an inward motion of the fingers subdomain-especially the O helix-to engage the primer-template and dNTP triphosphate. Distinctive structural features of mycobacterial Pol1 POL include a manganese binding site in the vestigial 3' exonuclease subdomain and a non-catalytic water-bridged magnesium complex at the protein-DNA interface. We report a crystal structure of the bifunctional FEN/EXO-POL apoenzyme that reveals the positions of two active site metals in the FEN/EXO domain.

Mycobacterial DNA polymerase I: activities and crystal structures of the POL domain as apoenzyme and in complex with a DNA primer-template and of the full-length FEN/EXO-POL enzyme.,Ghosh S, Goldgur Y, Shuman S Nucleic Acids Res. 2020 Feb 8. pii: 5730378. doi: 10.1093/nar/gkaa075. PMID:32034423[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

See Also

References

  1. Ghosh S, Goldgur Y, Shuman S. Mycobacterial DNA polymerase I: activities and crystal structures of the POL domain as apoenzyme and in complex with a DNA primer-template and of the full-length FEN/EXO-POL enzyme. Nucleic Acids Res. 2020 Feb 8. pii: 5730378. doi: 10.1093/nar/gkaa075. PMID:32034423 doi:http://dx.doi.org/10.1093/nar/gkaa075

6vde, resolution 2.71Å

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