Open AccessSmall RNAs and Small Proteins Involved in Resistance to Cell Envelope Stress and Acid Shock in Escherichia coli : Analysis of a Bar-Coded Mutant Collection
Author(s) -
Errett C. Hobbs,
Jillian L. Astarita,
Gisela Storz
Publication year - 2010
Publication title -
journal of bacteriology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.652
H-Index - 246
eISSN - 1067-8832
pISSN - 0021-9193
DOI - 10.1128/jb.00873-09
Subject(s) - biology , mutant , gene , cell envelope , genetics , escherichia coli , phenotype , mutation , microbiology and biotechnology
More than 80 small regulatory RNAs (sRNAs) and 60 proteins of 16 to 50 amino acids (small proteins) are encoded in theE scherichia coli genome. The vast majority of the corresponding genes have no known function. We screened 125 DNA bar-coded mutants to identify novel cell envelope stress and acute acid shock phenotypes associated with deletions of genes coding for sRNAs and small proteins. Nine deletion mutants (ssrA ,micA ,ybaM ,ryeF ,yqcG ,sroH ,ybhT ,yobF , andglmY ) were sensitive to cell envelope stress and two were resistant (rybB andblr ). Deletion mutants of genes coding for four small proteins (yqgB ,mgrB ,yobF , andyceO ) were sensitive to acute acid stress. We confirmed each of these phenotypes in one-on-one competition assays against otherwise-wild-typelacZ mutant cells. A more detailed investigation of the SsrA phenotype suggests that ribosome release is critical for resistance to cell envelope stress. The bar-coded deletion collection we generated can be screened for sensitivity or resistance to virtually any stress condition.