TY - JOUR
T1 - RNase T affects Escherichia coli growth and recovery from metabolic stress
AU - Padmanabha, K. P.
AU - Deutscher, M. P.
N1 - Copyright:
Copyright 2017 Elsevier B.V., All rights reserved.
PY - 1991
Y1 - 1991
N2 - To determine the essentiality and role of RNase T in RNA metabolism, we constructed an Escherichia coli chromosomal rnt::kan mutation by using gene replacement with a disrupted, plasmid-borne copy of the rnt gene. Cell extracts of a strain with mutations in RNases BN, D, II, and I and an interrupted rnt gene were devoid of RNase T activity, although they retained a low level (<10%) of exonucleolytic activity on tRNA-C-C[14C]A due to two other unidentified RNases. A mutant lacking tRNA nucleotidyltransferase in addition to the aforementioned RNAses accumulated only about 5% as much defective tRNA as did RNase T-positive cells, indicating that this RNase is responsible for essentially all tRNA end turnover in E. coli. tRNA from rnt::kan strains displayed a slightly reduced capacity to be aminoacylated, raising the possibility that RNase T may also participate in tRNA processing. Strains devoid of RNase T displayed slower growth rates than did the wild type, and this phenotype was accentuated by the absence of the other exoribonucleases. A strain lacking RNase T and other RNases displayed a normal response to UV irradiation and to the growth of bacteriophages but was severely affected in its ability to recover from a starvation regimen. The data demonstrate that the absence of RNase T affects the normal functioning of E. coli, but it can be compensated for to some degree by the presence of other RNases. Possible roles of RNase T in RNA metabolism are discussed.
AB - To determine the essentiality and role of RNase T in RNA metabolism, we constructed an Escherichia coli chromosomal rnt::kan mutation by using gene replacement with a disrupted, plasmid-borne copy of the rnt gene. Cell extracts of a strain with mutations in RNases BN, D, II, and I and an interrupted rnt gene were devoid of RNase T activity, although they retained a low level (<10%) of exonucleolytic activity on tRNA-C-C[14C]A due to two other unidentified RNases. A mutant lacking tRNA nucleotidyltransferase in addition to the aforementioned RNAses accumulated only about 5% as much defective tRNA as did RNase T-positive cells, indicating that this RNase is responsible for essentially all tRNA end turnover in E. coli. tRNA from rnt::kan strains displayed a slightly reduced capacity to be aminoacylated, raising the possibility that RNase T may also participate in tRNA processing. Strains devoid of RNase T displayed slower growth rates than did the wild type, and this phenotype was accentuated by the absence of the other exoribonucleases. A strain lacking RNase T and other RNases displayed a normal response to UV irradiation and to the growth of bacteriophages but was severely affected in its ability to recover from a starvation regimen. The data demonstrate that the absence of RNase T affects the normal functioning of E. coli, but it can be compensated for to some degree by the presence of other RNases. Possible roles of RNase T in RNA metabolism are discussed.
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U2 - 10.1128/jb.173.4.1376-1381.1991
DO - 10.1128/jb.173.4.1376-1381.1991
M3 - Article
C2 - 1704882
AN - SCOPUS:0026012161
VL - 173
SP - 1376
EP - 1381
JO - Journal of Bacteriology
JF - Journal of Bacteriology
SN - 0021-9193
IS - 4
ER -