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

J. Biol. Chem., Vol. 275, Issue 27, 20361-20367, July 7, 2000

This Article Full Text Full Text (PDF) All Versions of this Article: 275/27/20361    most recent M001238200v1 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 Thanedar, S. Articles by Varshney, U. Search for Related Content PubMed PubMed Citation Articles by Thanedar, S. Articles by Varshney, U. Social Bookmarking                      What's this?

The Fate of the Initiator tRNAs Is Sensitive to the Critical Balance between Interacting Proteins^*

Swapna Thanedar, N. Vinay Kumar^§, and Umesh Varshney^¶

From the Department of Microbiology and Cell Biology, Indian Institute of Science, Bangalore 560 012, India

Formylation of the initiator tRNA is essential for normal growth of Escherichia coli. The initiator tRNA containing the U35A36 mutation (CUA anticodon) initiates from UAG codon. However, an additional mutation at position 72 (72A  G) renders the tRNA (G72/U35A36) inactive in initiation because it is defective in formylation. In this study, we isolated U1G72/U35A36 tRNA containing a wobble base pair at 1-72 positions as an intragenic suppressor of the G72 mutation. The U1G72/U35A36 tRNA is formylated and participates in initiation. More importantly, we show that the mismatch at 1-72 positions of the initiator tRNA, which was thus far thought to be the hallmark of the resistance of this tRNA against peptidyl-tRNA hydrolase (PTH), is not sufficient. The amino acid attached to the initiator tRNA is also important in conferring protection against PTH. Further, we show that the relative levels of PTH and IF2 influence the path adopted by the initiator tRNAs in protein synthesis. These findings provide an important clue to understand the dual function of the single tRNA^Met in initiation and elongation, in the mitochondria of various organisms.

CiteULike

Complore

Connotea

Del.icio.us

Digg

Reddit

Technorati

This article has been cited by other articles:

				G. Das and U. Varshney Peptidyl-tRNA hydrolase and its critical role in protein biosynthesis. Microbiology, August 1, 2006; 152(Pt 8): 2191 - 2195. [Abstract] [Full Text] [PDF]

				G. Das, T. K. Dineshkumar, S. Thanedar, and U. Varshney Acquisition of a stable mutation in metY allows efficient initiation from an amber codon in Escherichia coli Microbiology, June 1, 2005; 151(6): 1741 - 1750. [Abstract] [Full Text] [PDF]

				B. S. Laursen, H. P. Sorensen, K. K. Mortensen, and H. U. Sperling-Petersen Initiation of Protein Synthesis in Bacteria Microbiol. Mol. Biol. Rev., March 1, 2005; 69(1): 101 - 123. [Abstract] [Full Text] [PDF]

				A. Stortchevoi, U. Varshney, and U. L. RajBhandary Common Location of Determinants in Initiator Transfer RNAs for Initiator-Elongator Discrimination in Bacteria and in Eukaryotes J. Biol. Chem., May 9, 2003; 278(20): 17672 - 17679. [Abstract] [Full Text] [PDF]

				T. K. Dineshkumar, S. Thanedar, C. Subbulakshmi, and U. Varshney An unexpected absence of queuosine modification in the tRNAs of an Escherichia coli B strain Microbiology, December 1, 2002; 148(12): 3779 - 3787. [Abstract] [Full Text] [PDF]

				S. Thanedar, T. K. Dineshkumar, and U. Varshney The Mere Lack of rT Modification in Initiator tRNA Does Not Facilitate Formylation-Independent Initiation in Escherichia coli J. Bacteriol., December 15, 2001; 183(24): 7397 - 7402. [Abstract] [Full Text] [PDF]