Exploration of the molecular structure of Escherichia coli cytochrome bo ubiquinol oxidase by genetic approach

Cytochrome bo ubiquinol oxidase is one of the two terminal ubiquinol oxidases in the aerobic respiratory chain of Escherichia coli. By deleting the intergenic region between the cyoA and cyoB and one base in the overlapping sequence between cyoB and cyoC, in-frame fusions are made between all three subunits (II-I-III), the resulting gene product still assembles as part of a functional oxidase. The fused subunit (II-I-III) contains 22 transmembrane spans. These data support the previously proposed topology of the subunits. The purified cytochrome bo oxidase contains four subunits. The observed molecular weight of subunit II by mass spectroscopy is considerably less than the calculated value from the deduced amino acid sequence of its corresponding gene cyoA. The similarity of the N-terminal signal sequence of subunit II with those of known lipoproteins suggest that it is modified by lipids. This is proved by demonstrating that subunit II incorporates radioactive palmitic acid.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Biochemistry

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2011

Author dc:creator

• Ma, Jixiang

Contributors dc:contributor

• Gennis, Robert B.

• Biology, Microbiology
• Chemistry, Biochemistry

Statement dc:rights

• Copyright 1995 Ma, Jixiang

Language dc:language

eng

Identifier

AAI9624422
(UMI)AAI9624422

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/20125