MicL, a new σE-dependent sRNA, combats envelope stress by repressing synthesis of Lpp, the major outer membrane lipoprotein.

ABSTRACT: In enteric bacteria, the transcription factor σ(E) maintains membrane homeostasis by inducing synthesis of proteins involved in membrane repair and two small regulatory RNAs (sRNAs) that down-regulate synthesis of abundant membrane porins. Here, we describe the discovery of a third σ(E)-dependent sRNA, MicL (mRNA-interfering complementary RNA regulator of Lpp), transcribed from a promoter located within the coding sequence of the cutC gene. MicL is synthesized as a 308-nucleotide (nt) primary transcript that is processed to an 80-nt form. Both forms possess features typical of Hfq-binding sRNAs but surprisingly target only a single mRNA, which encodes the outer membrane lipoprotein Lpp, the most abundant protein of the cell. We show that the copper sensitivity phenotype previously ascribed

SUBMITTER: Guo MS 

PROVIDER: S-EPMC4102768 | biostudies-literature | 2014 Jul

REPOSITORIES: biostudies-literature