Open AccessCarbon monoxide‐binding properties of the cytochrome bo quinol oxidase complex in Escherichia coli are changed by copper deficiency in continuous culture
Author(s) -
Ciccognani Diana T.,
Hughes Martin N.,
Poole Robert K.
Publication year - 1992
Publication title -
fems microbiology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.899
H-Index - 151
eISSN - 1574-6968
pISSN - 0378-1097
DOI - 10.1111/j.1574-6968.1992.tb05278.x
Subject(s) - cytochrome c oxidase , copper , cytochrome , electron transport complex iv , oxidase test , chemistry , cytochrome b , escherichia coli , carbon monoxide , copper deficiency , photodissociation , photochemistry , biochemistry , enzyme , catalysis , organic chemistry , mitochondrial dna , gene
A strain of Escherichia coli having elevated levels of cytochrome bo and lacking the cytochrome bd quinol oxidase was grown in chemostat culture at low copper levels. Such cells had lowered levels of copper and of total cytochrome b. Cytochrome o concentration was unchanged when assayed by conventional CO difference spectroscopy, but apparently diminished by 80% in copper‐deficient cells as determined by photodissociation of bound CO at 193 K. This is attributed to depletion of copper in the oxidase of copper‐deficient cells, causing rapid recombination of photodissociated CO to haem O. CO recombination was also more sensitive to low intensities of actinic light in copper‐depleted oxidase. The results illustrate a further similarity between the active sites of o‐ and aa 3 ‐type terminal oxidase.