Journal
FEMS MICROBIOLOGY LETTERS
Volume 232, Issue 1, Pages 107-112Publisher
OXFORD UNIV PRESS
DOI: 10.1016/S0378-1097(04)00068-0
Keywords
chromate resistance; random mutation; membrane protein; Pseudomonas; plasmid
Categories
Ask authors/readers for more resources
The chrA gene of Pseudomonas aeruginosa plasmid pUM505 encodes the hydrophobic protein ChrA, which confers resistance to chromate by the energy-dependent efflux of chromate ions. Chromate-sensitive mutants were isolated by in vivo random mutagenesis. Transport experiments with cell suspensions of selected mutants showed that (CrO42-)-Cr-51 extrusion was drastically lowered as compared to suspensions of the strain with the wild-type plasmid, confirming that the mutations affected a chromate efflux system. DNA sequence analysis showed that most point mutations affected amino acids clustered in the N-terminal half of ChrA, altering either cytoplasmic regions or transmembrane segments, and replaced residues moderately to highly conserved in ChrA homologs. PhoA and LacZ translational fusions were used to confirm the membrane topology at the N-terminal half of the ChrA protein. (C) 2004 Federation of European Microbiological Societies. Published by Elsevier B.V. All rights reserved.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available