RNase T is responsible for the end-turnover of tRNA in Escherichia coli.
A mutant strain deficient in RNase T was isolated and used to study the role of this enzyme in Escherichia coli. Strains lacking as much as 70% of RNase T activity, alone or in combination with the absence of other RNases, display normal growth properties. However, in cca strains, which lack tRNA nucleotidyltransferase, RNase T-deficient derivatives accumulate lower levels of defective tRNA and grow at increased rates compared to their RNase T+ parents. Slow-growing cca strains revert to a faster-growing form that contains less defective tRNA but which is still cca. All of these strains have decreased levels of RNase T. These data indicate that RNase T is responsible for nucleotide removal during the tRNA end-turnover process and that the amount of defective tRNA in cells is determined by the relative levels of RNase T and tRNA nucleotidyltransferase.
Deutscher
M P
MP
Marlor
C W
CW
Zaniewski
R
R
D001426:Bacterial Proteins / Q000235:genetics / Q000502:physiology*; D004926:Escherichia coli / Q000201:enzymology* / Q000235:genetics / Q000502:physiology; D005095:Exoribonucleases / Q000235:genetics / Q000502:physiology*; D012316:RNA Nucleotidyltransferases / Q000502:physiology; D012323:RNA Processing, Post-Transcriptional; D012329:RNA, Bacterial / Q000378:metabolism*; D012343:RNA, Transfer / Q000378:metabolism*
D001426:Bacterial Proteins; D012329:RNA, Bacterial; D012343:RNA, Transfer; D012316:RNA Nucleotidyltransferases; C023198:tRNA nucleotidyltransferase; D005095:Exoribonucleases; C042081:exoribonuclease T