Affiliation:
1. Institut für Medizinische Mikrobiologie, Medizinische Hochschule Hannover, 30623 Hannover, Germany
Abstract
ABSTRACT
Chromosomally acquired streptomycin resistance is frequently due to mutations in the gene encoding the ribosomal protein S12,
rpsL
. The presence of several rRNA operons (
rrn
) and a single
rpsL
gene in most bacterial genomes prohibits the isolation of streptomycin-resistant mutants in which resistance is mediated by mutations in the 16S rRNA gene (
rrs
). Three strains were constructed in this investigation:
Mycobacterium smegmatis rrnB
,
M. smegmatis rpsL
3+
, and
M. smegmatis rrnB rpsL
3+
.
M. smegmatis rrnB
carries a single functional
rrn
operon, i.e.,
rrnA
(comprised of 16S, 23S, and 5S rRNA genes) and a single
rpsL
+
gene;
M. smegmatis rpsL
3+
is characterized by the presence of two
rrn
operons (
rrnA
and
rrnB
) and three
rpsL
+
genes; and
M. smegmatis rrnB rpsL
3+
carries a single functional
rrn
operon (
rrnA
) and three
rpsL
+
genes. By genetically altering the number of
rpsL
and
rrs
alleles in the bacterial genome, mutations in
rrs
conferring streptomycin resistance could be selected, as revealed by analysis of streptomycin-resistant derivatives of
M. smegmatis rrnB rpsL
3+
. Besides mutations well known to confer streptomycin resistance, novel streptomycin resistance conferring mutations were isolated. Most of the mutations were found to map to a functional pseudoknot structure within the 530 loop region of the 16S rRNA. One of the mutations observed, i.e., 524G→C, severely distorts the interaction between nucleotides 524G and 507C, a Watson-Crick interaction which has been thought to be essential for ribosome function. The use of the single rRNA allelic
M. smegmatis
strain should help to elucidate the principles of ribosome-drug interactions.
Publisher
American Society for Microbiology
Subject
Infectious Diseases,Pharmacology (medical),Pharmacology
Cited by
138 articles.
订阅此论文施引文献
订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献