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Characterization of the osmoregulated Escherichia coli proU promoter and identification of ProV as a membrane‐associated protein
Author(s) -
May G.,
Faatz E.,
Lucht J. M.,
Haardt M.,
Bolliger M.,
Bremer E.
Publication year - 1989
Publication title -
molecular microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.857
H-Index - 247
eISSN - 1365-2958
pISSN - 0950-382X
DOI - 10.1111/j.1365-2958.1989.tb00138.x
Subject(s) - operon , biology , escherichia coli , lac operon , osmotic concentration , permease , promoter , transcription (linguistics) , gene , biochemistry , microbiology and biotechnology , gene expression , linguistics , philosophy
Summary The Escherichia coli proU operon encodes a high‐affinity, binding‐protein‐dependent transport system for the osmoprotectant glycine betaine. Expression of proU is osmoregulated, and transcription of this operon is greatly increased In cells grown at high osmolarity. Characterization of the proU operon and its promoter provided results similar to those published elsewhere (Gowrishankar, 1989; Stirling et al. , 1989). The previously identified proU601 mutation, which leads to increased proU expression both at low‐and high osmolarity, is a G to A transition in the Pribnow box of the proU promoter, which increases the homology of the ‐10 region to the consensus sequence of E. coli promoters. Using an antiserum raised against a ProV‐β‐galactosidase hybrid protein, we have identified ProV as a protein associated with the cytoplasmic membrane. This cellular location is consistent with its proposed role as the energy ‐coupling component of the ProU transport system.