SsrA-mediated tagging and proteolysis of LacI and its role in the regulation of lac operon

Abo, T; Inada, T; Ogawa, K; Aiba, H

HERO ID

1617050

Reference Type

Journal Article

Year

2000

Language

English

PMID

10899129

HERO ID 1617050
In Press No
Year 2000
Title SsrA-mediated tagging and proteolysis of LacI and its role in the regulation of lac operon
Authors Abo, T; Inada, T; Ogawa, K; Aiba, H
Journal EMBO Journal
Volume 19
Issue 14
Page Numbers 3762-3769
Abstract SsrA RNA of Escherichia coli, also known as 10Sa RNA or tmRNA, acts both as tRNA and mRNA when ribosomes are paused at the 3' end of an mRNA lacking a stop codon. This process, referred to as trans-translation, leads to the addition of a short peptide tag to the C-terminus of the incomplete nascent polypeptide. The tagged polypeptide is then degraded by C-terminal-specific proteases. Here, we focused on endogenous targets for the SsrA system and on a potential regulatory role of SsrA RNA. First, we show that trans-translation events occur frequently in normally growing E. COLI: cells. More specifically, we report that the lacI mRNA encoding Lac repressor (LacI) is a specific natural target for trans-translation. The binding of LacI to the lac operators results in truncated lacI mRNAs that are, in turn, recognized by the SsrA system. The SsrA-mediated tagging and proteolysis of LacI appears to play a role in cellular adaptation to lactose availability by supporting a rapid induction of lac operon expression.
Doi 10.1093/emboj/19.14.3762
Pmid 10899129
Is Certified Translation No
Dupe Override No
Is Public Yes
Language Text English