Previous Article | Next Article ![]()
J. Bacteriol., May 1995, 2858-2862, Vol 177, No. 10
D Mangroo, PA Limbach, JA McCloskey and UL RajBhandary
Initiator tRNAs from eubacteria and chloroplasts lack a base modification
next to the anticodon. This is in contrast to virtually all other tRNAs
from these sources. We show that a mutant Escherichia coli initiator tRNA
which has an anticodon sequence change from CAU to CUA now has a
2-methylthio-N6-(delta 2-isopentenyl)adenosine (ms2i6A) modification,
produced by posttranscriptional modification of A, next to the anticodon.
This newly acquired base modification may be important for the function of
the mutant tRNA in initiation. In a miaA mutant strain of E. coli defective
in biosynthesis of ms2i6A, the mutant initiator tRNA is 10- to 12-fold less
active in initiation. The mutant tRNA is aminoacylated and formylated
normally in the miaA strain. Thus, the absence of the base modification
affects the activity of the mutant tRNA at a step subsequent to its
formylation.
Copyright © 1995, American Society for Microbiology
An anticodon sequence mutant of Escherichia coli initiator tRNA: possible importance of a newly acquired base modification next to the anticodon on its activity in initiation
Department of Biology, Massachusetts Institute of Technology, Cambridge 02139, USA.
This article has been cited by other articles:
Copyright © 2009 by the American Society for Microbiology. For an alternate route to Journals.ASM.org, visit: http://intl-journals.asm.org | More Info»