HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Martin, S. A. Articles by Moss, B. Search for Related Content PubMed PubMed Citation Articles by Martin, S. A. Articles by Moss, B. Social Bookmarking                      What's this?

JBC, Vol. 250, Issue 24, 9330-9335, Dec, 1975

Modification of RNA by mRNA guanylyltransferase and mRNA (guanine-7-)methyltransferase from vaccinia virions

S. A. Martin and B. Moss

A purified enzyme system isolated from vaccinia virus cores has been shown to modify the 5' termini of viral mRNA and synthetic poly(A) and poly(G) to form the structures m7G(5')pppA- and m7G(5')pppG-. The enzyme system has both guanylyltransferase and methyltransferase activities. The GTP:mRNA guanylyltransferase activity incorporates GMP into the 5' terminus via a 5'-5' triphosphate bond. The properties of this reaction are: (a) of the four nucleoside triphosphates only GTP is a donor, (b) mRNA with two phosphates at the 5' terminus is an acceptor while RNA with a single 5'-terminal phosphate is not, (c) Mg2+ is required, (d) the pH optimum is 7.8, (e) PP1 is a strong inhibitor, and (f) the reverse reaction, namely the formation of GTP from PP1 and RNA containing the 5'-terminal structure G(5')pppN-, readily occurs. The S-adenosylmethionine:mRNA(guanine-7-)methyltransferase activity catalyzes the methylation of the 5'-terminal guanosine. This reaction exhibits the following characteristics: (a) mRNA with the 5'-terminal sequences G(5')pppA- and G(5')pppG- are acceptors, (b) only position 7 of the terminal guanosine is methylated; internal or conventional 5'-terminal guanosine residues are not methylated, (c) the reaction is not dependent upon GTP or divalent cations, (d) optimal activity is observed in a broad pH range around neutrality, (e) the reaction is inhibited by S-adenosylhomocysteine. Both the guanylyltransferase and methyltransferase reactions exhibit bisubstrate kinetics and proceed via a sequential mechanism. The reactions may be summarized: (see article).
CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    What's this?

This article has been cited by other articles:

				D. Walsh, C. Arias, C. Perez, D. Halladin, M. Escandon, T. Ueda, R. Watanabe-Fukunaga, R. Fukunaga, and I. Mohr Eukaryotic Translation Initiation Factor 4F Architectural Alterations Accompany Translation Initiation Factor Redistribution in Poxvirus-Infected Cells Mol. Cell. Biol., April 15, 2008; 28(8): 2648 - 2658. [Abstract] [Full Text] [PDF]

				S. Parrish and B. Moss Characterization of a Second Vaccinia Virus mRNA-Decapping Enzyme Conserved in Poxviruses J. Virol., December 1, 2007; 81(23): 12973 - 12978. [Abstract] [Full Text] [PDF]

				Y. Takagi, S. Sindkar, D. Ekonomidis, M. P. Hall, and C. K. Ho Trypanosoma brucei Encodes a Bifunctional Capping Enzyme Essential for Cap 4 Formation on the Spliced Leader RNA J. Biol. Chem., June 1, 2007; 282(22): 15995 - 16005. [Abstract] [Full Text] [PDF]

				B. Schwer, S. Hausmann, S. Schneider, and S. Shuman Poxvirus mRNA Cap Methyltransferase: BYPASS OF THE REQUIREMENT FOR THE STIMULATORY SUBUNIT BY MUTATIONS IN THE CATALYTIC SUBUNIT AND EVIDENCE FOR INTERSUBUNIT ALLOSTERY J. Biol. Chem., July 14, 2006; 281(28): 18953 - 18960. [Abstract] [Full Text] [PDF]

				S. Hausmann, S. Zheng, C. Fabrega, S. W. Schneller, C. D. Lima, and S. Shuman Encephalitozoon cuniculi mRNA Cap (Guanine N-7) Methyltransferase: METHYL ACCEPTOR SPECIFICITY, INHIBITION BY S-ADENOSYLMETHIONINE ANALOGS, AND STRUCTURE-GUIDED MUTATIONAL ANALYSIS J. Biol. Chem., May 27, 2005; 280(21): 20404 - 20412. [Abstract] [Full Text] [PDF]

				N. Saha, S. Shuman, and B. Schwer Yeast-Based Genetic System for Functional Analysis of Poxvirus mRNA Cap Methyltransferase J. Virol., July 1, 2003; 77(13): 7300 - 7307. [Abstract] [Full Text] [PDF]

				B. Schwer, N. Saha, X. Mao, H.-W. Chen, and S. Shuman Structure-Function Analysis of Yeast mRNA Cap Methyltransferase and High-Copy Suppression of Conditional Mutants by AdoMet Synthase and the Ubiquitin Conjugating Enzyme Cdc34p Genetics, August 1, 2000; 155(4): 1561 - 1576. [Abstract] [Full Text]

				N. Ramadevi, N. J. Burroughs, P. P. C. Mertens, I. M. Jones, and P. Roy Capping and methylation of mRNA by purified recombinant VP4 protein of bluetongue virus PNAS, November 10, 1998; 95(23): 13537 - 13542. [Abstract] [Full Text] [PDF]

				M. G. Thomas, T. B. Thompson, I. Rayment, and J. C. Escalante-Semerena Analysis of the Adenosylcobinamide Kinase/Adenosylcobinamide-phosphate Guanylyltransferase (CobU) Enzyme of Salmonella typhimurium LT2. IDENTIFICATION OF RESIDUE His-46 AS THE SITE OF GUANYLYLATION J. Biol. Chem., September 1, 2000; 275(36): 27576 - 27586. [Abstract] [Full Text] [PDF]