Download MendeleyCrystal structures of the vaccinia virus polyadenylate polymerase heterodimer: insights into ATP selectivity and processivity.
Moure, C.M., Bowman, B.R., Gershon, P.D., Quiocho, F.A.(2006) Mol Cell 22: 339-349
- PubMed: 16678106
- DOI: https://doi.org/10.1016/j.molcel.2006.03.015
- Primary Citation of Related Structures:
2GA9, 2GAF - PubMed Abstract:
Polyadenylation of mRNAs in poxviruses, crucial for virion maturation, is carried out by a poly(A) polymerase heterodimer composed of a catalytic component, VP55, and a processivity factor, VP39. The ATP-gamma-S bound and unbound crystal structures of the vaccinia polymerase reveal an unusual architecture for VP55 that comprises of N-terminal, central or catalytic, and C-terminal domains with different topologies and that differs from many polymerases, including the eukaryotic poly(A) polymerases. Residues in the active site of VP55, located between the catalytic and C-terminal domains, make specific interactions with the adenine of the ATP analog, establishing the molecular basis of ATP recognition. VP55's concave surface docks the globular VP39. A model for RNA primer binding that involves all three VP55 domains and VP39 is proposed. The model supports biochemical evidence that VP39 functions as a processivity factor by partially enclosing the RNA primer at the heterodimer interface.
Organizational Affiliation:
Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, Texas 77030, USA.
