Cytosine 73 is a discriminator nucleotide in vivo for histidyl-tRNA in Escherichia coli

The acceptor helix of histidine tRNAs in Escherichia coli is capped by a unique base pair in which the cytosine at the discriminator position is paired with an extra guanosine at -1. In previous in vitro studies, the presence of the G-1:C73 base pair was found to be required to obtain both optimal h...

Full description

Saved in:
Bibliographic Details
Published in:The Journal of biological chemistry 1994-04, Vol.269 (13), p.10022-10027
Main Authors: WEN YAN, FRANCKLYN, C
Format: Article
Language:English
Subjects:
Base Composition
Base Sequence
beta-Galactosidase - biosynthesis
Biological and medical sciences
Cytosine
DNA Primers
Escherichia coli
Escherichia coli - metabolism
Fundamental and applied biological sciences. Psychology
Genes, Bacterial
Genes, Suppressor
Histidine-tRNA Ligase - metabolism
Models, Structural
Molecular and cellular biology
Molecular genetics
Molecular Sequence Data
Mutagenesis, Site-Directed
Nucleic Acid Conformation
Oligodeoxyribonucleotides
RNA, Transfer, His - genetics
RNA, Transfer, His - metabolism
Suppression, Genetic
Translation. Translation factors. Protein processing
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:The acceptor helix of histidine tRNAs in Escherichia coli is capped by a unique base pair in which the cytosine at the discriminator position is paired with an extra guanosine at -1. In previous in vitro studies, the presence of the G-1:C73 base pair was found to be required to obtain both optimal histidylation by histidyl-tRNA synthetase and accurate 5' processing by RNase P. We investigated the role of G-1:C73 in histidine tRNA identity and found that nucleotide substitutions conferred mischarging by other amino acids in a pattern that correlated with the discriminator base and not with the extra nucleotide at -1. As shown by primer extension experiments, the relatively minor role of the -1 nucleotide in vivo could be attributed to altered RNase P processing. These studies show that interactions of tRNAs in vivo both with RNase P during tRNA biosynthesis and with the pool of aminoacyl-tRNA synthetases can modulate the effects of substitutions at recognition nucleotides, eliciting changes in transfer RNA identity.
ISSN:0021-9258
1083-351X
DOI:10.1016/s0021-9258(17)36984-3