title: Low ubiquinone content in Escherichia coli causes thiol hypersensitivity.
abstract: Thiol hypersensitivity in a mutant of Escherichia coli (IS16) was reversed by complementation with a plasmid that carried the ubiX gene. The mutant had low ubiquinone content. Complementation elevated the ubiquinone level and eliminated thiol hypersensitivity. Analysis of chromosomal ubiX genes indicated that both parent and mutant strains were ubiX mutants. The low ubiquinone content of IS16 was possibly caused by a ubiD ubiX genotype. A ubiA mutant also exhibited thiol hypersensitivity. Neither IS16 nor the ubiA mutant strain could produce alkaline phosphatase (in contrast to their parent strains) after 2 h of induction, thus showing Dsb- phenotypes. The phenomena of thiol hypersensitivity and low ubiquinone content may be linked by their connections to the periplasmic disulfide bond redox machinery.
authors.affiliation: Department of Biochemistry, Loma Linda University School of Medicine, Loma Linda, California 92350, USA.
authors.forename: H
authors.initials: H
authors.lastname: Zeng
authors.forename: I
authors.initials: I
authors.lastname: Snavely
authors.forename: P
authors.initials: P
authors.lastname: Zamorano
authors.forename: G T
authors.initials: GT
authors.lastname: Javor
mesh_terms: D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism; D001483:Base Sequence; D002262:Carboxy-Lyases; D004342:Drug Hypersensitivity; D004926:Escherichia coli / Q000187:drug effects* / Q000235:genetics / Q000378:metabolism; D029968:Escherichia coli Proteins; D005816:Genetic Complementation Test; D008969:Molecular Sequence Data; D013438:Sulfhydryl Compounds / Q000494:pharmacology*; D014451:Ubiquinone / Q000235:genetics / Q000378:metabolism*
chemical_list: D001426:Bacterial Proteins; D029968:Escherichia coli Proteins; D013438:Sulfhydryl Compounds; D014451:Ubiquinone; D002262:Carboxy-Lyases; C113304:ubiX protein, E coli