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

This Article Full Text Full Text (PDF) All Versions of this Article: rna.399607v1 13/3/404    most recent 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 Wilkinson, M. L. Articles by Phizicky, E. M. Search for Related Content PubMed PubMed Citation Articles by Wilkinson, M. L. Articles by Phizicky, E. M. Social Bookmarking                   What's this?

The 2'-O-methyltransferase responsible for modification of yeast tRNA at position 4

¹ Department of Biochemistry and Biophysics, University of Rochester School of Medicine, Rochester, New York 14642, USA
² Department of Chemistry, DePauw University, Greencastle, Indiana 46135, USA

The methylation of the ribose 2'-OH of RNA occurs widely in nature and in all stable RNAs and occurs at five positions in yeast tRNA. 2'-O-methylation of tRNA at position 4 is interesting because it occurs in the acceptor stem (which is normally undermodified), it is the only 2'-O-methylation that occurs in the middle of a duplex region in tRNA, the modification is conserved in eukaryotes, and the features of the tRNA necessary for substrate recognition are poorly defined. We show here that Saccharomyces cerevisiae ORF YOL125w (TRM13) is necessary and sufficient for 2'-O-methylation at position 4 of yeast tRNA. Biochemical analysis of the S. cerevisiae proteome shows that Trm13 copurifies with 2'-O-methylation activity, using tRNA^Gly(GCC) as a substrate, and extracts made from a trm13- strain have undetectable levels of this activity. Trm13 is necessary for activity in vivo because tRNAs isolated from a trm13- strain lack the corresponding 2'-O-methylated residue for each of the three known tRNAs with this modification. Trm13 is sufficient for 2'-O-methylation at position 4 in vitro since yeast Trm13 protein purified after expression in Escherichia coli has the same activity as that produced in yeast. Trm13 protein binds substrates tRNA^His and tRNA^Gly(GCC) with K_D values of 85 ± 8 and 100 ± 14 nM, respectively, and has a K_M for tRNA^His of 10 nM, but binds nonsubstrate tRNAs very poorly (K_D > 1 µM). Trm13 is conserved in eukaryotes, but there is no sequence similarity between Trm13 and other known methyltransferases.

Keywords: tRNA methyltransferase; Trm13; 2'-O-methylation; S. cerevisiae ; tRNA processing; tRNA modification

CiteULike    Connotea    Del.icio.us    Digg    Reddit    Technorati    What's this?

This article has been cited by other articles:

				L. Kotelawala, E. J. Grayhack, and E. M. Phizicky Identification of yeast tRNA Um44 2'-O-methyltransferase (Trm44) and demonstration of a Trm44 role in sustaining levels of specific tRNASer species RNA, January 1, 2008; 14(1): 158 - 169. [Abstract] [Full Text] [PDF]

				L. Pena-Castillo and T. R. Hughes Why Are There Still Over 1000 Uncharacterized Yeast Genes? Genetics, May 1, 2007; 176(1): 7 - 14. [Abstract] [Full Text] [PDF]