Abstract
The weight of current evidence suggests that RNA 2′-O-MTases employ an SN2 mechanism with an in-line attack of the target nucleophile upon the methyl group of the AdoMet cofactor. It has been suggested that, like the phosphohydrolytic enzymes, ribozymes, and nucleic acid polymerases, the RNA 2′-O-MTases initially activate the substrate's attacking hydroxyl oxygen by deprotonation. Here, evidence is presented that the vaccinia virus mRNA cap specific 2′-O-MTase VP39 does not promote RNA 2′-oxyanion formation but that instead it acts by steering a hydroxyl oxygen orbital toward the cofactor methyl center.
Original language | English (US) |
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Pages (from-to) | 5680-5687 |
Number of pages | 8 |
Journal | Biochemistry |
Volume | 43 |
Issue number | 19 |
DOIs | |
State | Published - May 18 2004 |