Please use this identifier to cite or link to this item: https://scholarbank.nus.edu.sg/handle/10635/112017
Title: Point mutations which drastically affect the polymerization activity of encephalomyocarditis virus RNA-dependent RNA polymerase correspond to the active site of Eacherichia coli DNA polymerase I
Authors: Sankar, S. 
Porter, A.G. 
Issue Date: 15-May-1992
Citation: Sankar, S.,Porter, A.G. (1992-05-15). Point mutations which drastically affect the polymerization activity of encephalomyocarditis virus RNA-dependent RNA polymerase correspond to the active site of Eacherichia coli DNA polymerase I. Journal of Biological Chemistry 267 (14) : 10168-10176. ScholarBank@NUS Repository.
Abstract: The inhibitor sensitivity and functional domains of recombinant encephalomyocarditis (EMC) virus RNA-dependent RNA polymerase (3Dpol) have been extensively analyzed. The inhibitor profiles of EMC virus 3Dpol and Escherichia coli DNA-dependent RNA polymerase are distinct, and experiments with substrate analogs indicate that EMC virus 3Dpol lacks reverse transcriptase activity. Twenty amino acid substitutions were engineered in EMC virus 3Dpol based on sequence alignments of viral RNA-dependent RNA polymerases that identified conserved amino acid residues within motifs. Ten out of 17 conservative substitutions within the four most conserved motifs reduced the RNA polymerase activity of the mutants to 0-6% of the activity of the wild-type enzyme, demonstrating the importance of these amino acids in the structure and/or function of EMC virus 3Dpol. Remarkably, 5 of the 10 mutations in EMC virus 3Dpol which had the most drastic effect on its RNA polymerase activity (D240E, S293T, N302Q, G332A, and D333E) were found to correspond to active site residues in E. coli DNA-dependent DNA polymerase I (Klenow). Our results reveal that a basic structural and functional framework is conserved in the most distantly related classes of nucleic acid polymerases and demonstrate the validity of modeling the active site of an RNA-dependent RNA polymerase on the known structure of a DNA polymerase.
Source Title: Journal of Biological Chemistry
URI: http://scholarbank.nus.edu.sg/handle/10635/112017
ISSN: 00219258
Appears in Collections:Staff Publications

Show full item record
Files in This Item:
There are no files associated with this item.

Page view(s)

33
checked on Oct 14, 2021

Google ScholarTM

Check


Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.