TY - JOUR
T1 - The tRNA processing enzyme RNase T is essential for maturation of 5S RNA
AU - Li, Zhongwei
AU - Deutscher, Murray P.
PY - 1995/7/18
Y1 - 1995/7/18
N2 - The maturation of 5S RNA in Escherichia coli is poorly understood. Although it is known that large precursors of 5S RNA accumulate in mutant cells lacking the endoribonuclease RNase E, almost nothing is known about how the mature 5' and 3' termini of these molecules are generated. We have examined 5S RNA maturation in wild-type and single- or multiple- exoribonuclease-deficient cells by Northern blot and primer-extension analysis. Our results indicate that no mature 5S RNA is made in RNase T- deficient strains. Rather, 5S RNA precursors containing predominantly 2 extra nucleotides at the 3' end accumulate. Apparently, these 5S RNAs are functional inasmuch as mutant cells are viable, growing only slightly slower than wild type. Purified RNase T can remove the extra 3' residues, showing that it is directly involved in the trimming reaction. In contrast, mutations affecting other 3' exoribonucleases have no effect on 5S RNA maturation. Approximately 90% of the 5S RNAs in both wild-type and RNase T- cells contain mature 5' termini, indicating that 5' processing is independent of RNase T action. These data identify the enzyme responsible for generating the mature 3' terminus of 5S RNA molecules and also demonstrate that a completely processed 5S RNA molecule is not essential for cell survival.
AB - The maturation of 5S RNA in Escherichia coli is poorly understood. Although it is known that large precursors of 5S RNA accumulate in mutant cells lacking the endoribonuclease RNase E, almost nothing is known about how the mature 5' and 3' termini of these molecules are generated. We have examined 5S RNA maturation in wild-type and single- or multiple- exoribonuclease-deficient cells by Northern blot and primer-extension analysis. Our results indicate that no mature 5S RNA is made in RNase T- deficient strains. Rather, 5S RNA precursors containing predominantly 2 extra nucleotides at the 3' end accumulate. Apparently, these 5S RNAs are functional inasmuch as mutant cells are viable, growing only slightly slower than wild type. Purified RNase T can remove the extra 3' residues, showing that it is directly involved in the trimming reaction. In contrast, mutations affecting other 3' exoribonucleases have no effect on 5S RNA maturation. Approximately 90% of the 5S RNAs in both wild-type and RNase T- cells contain mature 5' termini, indicating that 5' processing is independent of RNase T action. These data identify the enzyme responsible for generating the mature 3' terminus of 5S RNA molecules and also demonstrate that a completely processed 5S RNA molecule is not essential for cell survival.
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U2 - 10.1073/pnas.92.15.6883
DO - 10.1073/pnas.92.15.6883
M3 - Article
C2 - 7542780
AN - SCOPUS:0029151159
VL - 92
SP - 6883
EP - 6886
JO - Proceedings of the National Academy of Sciences of the United States of America
JF - Proceedings of the National Academy of Sciences of the United States of America
SN - 0027-8424
IS - 15
ER -