Generation of pre-tRNAs from polycistronic operons is the essential function of RNase P in Escherichia coli
Generation of pre-tRNAs from polycistronic operons is the essential function of RNase P in Escherichia coli
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DOI：
10.1093/nar/gkz1188
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发表时间：
2020-03-18
影响因子：
14.9
通讯作者：
Kushner, Sidney R.
中科院分区：
文献类型：
--
作者：
Mohanty, Bijoy K.;Agrawal, Ankit;Kushner, Sidney R.
Ribonuclease P (RNase P) is essential for the 5'-end maturation of tRNAs in all kingdoms of life. In Escherichia coli, temperature sensitive mutations in either its protein (rnpA49) and or RNA (rnpB709) sub-units lead to inviability at nonpermissive temperatures. Using the rnpA49 temperature sensitive allele, which encodes a partially defective RNase P at the permissive temperature, we show here for the first time that the processing of RNase P-dependent poly-cistronic tRNA operons to release pre-tRNAs is the essential function of the enzyme, since the majority of 5'-immature tRNAs can be aminoacylated unless their 5'-extensions >= 8 nt. Surprisingly, the failure of 5'-end maturation elicits increased polyadenylation of some pre-tRNAs by poly(A) polymerase I (PAP I), which exacerbates inviability. The absence of PAP I led to improved aminoacylation of 5'-immature tRNAs. Our data suggest a more dynamic role for PAP I in maintaining functional tRNA levels in the cell.
