- PMID:
8612277
- Authors:
- Hodel AE, Gershon PD, Shi X, Quiocho FA
- Title:
- The 1.85 A structure of vaccinia protein VP39: a bifunctional enzyme that participates in the modification of both mRNA ends.
- Journal:
- Cell. 1996 Apr 19;85(2):247-56.
- Abstract:
- VP39 is a bifunctional vaccinia virus protein that acts as both an mRNA cap-specific RNA 2'-O-methyltransferase and a poly(A) polymerase processivity factor. Here, we report the 1.85 A crystal structure of a VP39 variant complexed with its AdoMet cofactor. VP39 comprises a single core domain with structural similarity to the catalytic domains of other methyltransferases. Surface features and mutagenesis data suggest two possible RNA-binding sites with novel underlying architecture, one of which forms a cleft spanning the region adjacent to the methyltransferase active site. This report provides a prototypic structure for an RNA methyltransferase, a protein that interacts with the mRNA 5' cap, and an intact poxvirus protein.