Conferring RNA polymerase Activity to a DNA polymerase: A single residue in reverse transcriptase controls substrate selection

作者：Guangxia Gao, Marianna O. Orlova, Millie M. Georgiadis, Wayne A. Hendrickson, Stephen P. Goff · 发表于：Proceedings of the National Academy of Sciences · 年份：1997 · DOI：10.1073/pnas.94.2.407 · 被引用次数：188 · 研究领域：HIV/AIDS drug development and treatment、HIV Research and Treatment、DNA and Nucleic Acid Chemistry

The traditional classification of nucleic acid polymerases as either DNA or RNA polymerases is based, in large part, on their fundamental preference for the incorporation of either deoxyribonucleotides or ribonucleotides during chain elongation. The refined structure determination of Moloney murine leukemia virus reverse transcriptase, a strict DNA polymerase, recently allowed the prediction that a single amino acid residue at the active site might be responsible for the discrimination against the 2'OH group of an incoming ribonucleotide. Mutation of this residue resulted in a variant enzyme now capable of acting as an RNA polymerase. In marked contrast to the wild-type enzyme, the K(m) of the mutant enzyme for ribonucleotides was comparable to that for deoxyribonucleotides. The results are consistent with proposals of a common evolutionary origin for both classes of enzymes and support models of a common mechanism of nucleic acid synthesis underlying catalysis by all such polymerases.