Molybdopterin in carbon monoxide oxidase from carboxydotrophic bacteria
The carbon monoxide oxidases (COXs) purified from the carboxydotrophic bacteria Pseudomonas carboxydohydrogena and Pseudomonas carboxydoflava were found to be molybdenum hydroxylases, identical in cofactor composition and spectral properties to the recently characterized enzyme from Pseudomonas carboxydovorans. All three enzymes exhibited a cofactor composition of two flavin adenine dinucleotides, two molybdenums, eight irons and eight labile sulfides per dimeric molecule, typical for molybdenum-containing iron-sulfur flavoproteins. The millimolar extinction coefficient of the COXs at 450 nm was 72 (per two flavin adenine dinucleotides), a value similar to that of milk xanthine oxidase and chicken liver xanthine dehydrogenase at 450 nm. That molybdopterin, the novel prosthetic group of the molybdenum cofactor of a variety of molybdoenzymes is also a constituent of COXs from carboxydotrophic bacteria is indicated by the formation of identical fluorescent cofactor derivatives, by complementation of the nitrate reductase activity in extracts of Neurospora crassa nit-1, and by the presence of organic phosphate additional to flavin adenine dinucleotides. Molybdopterin is tightly but noncovalently bound to the protein. COX, sulfite oxidase, xanthine oxidase, and xanthine dehydrogenase each contains 2 mol of molybdopterin per mol of enzyme. The presence of a trichloroacetic acid-releasable, so-far-unidentified, phosphorous-containing moiety in COX is suggested by the results of phosphate analysis.
- Research Organization:
- Universitaet Goettingen, West Germany
- OSTI ID:
- 6265237
- Journal Information:
- J. Bacteriol.; (United States), Vol. 157:2
- Country of Publication:
- United States
- Language:
- English
Similar Records
Biochemical characterization of the chlB mutant of E. coli
Crystal structure of DMSO reductase: Redox-linked changes in molybdopterin coordination
Related Subjects
OXIDOREDUCTASES
STRUCTURAL CHEMICAL ANALYSIS
PSEUDOMONAS
METABOLISM
CARBON MONOXIDE
MOLYBDENUM
OXIDATION
PHOSPHORUS
BACTERIA
CARBON COMPOUNDS
CARBON OXIDES
CHALCOGENIDES
CHEMICAL REACTIONS
ELEMENTS
ENZYMES
METALS
MICROORGANISMS
NONMETALS
OXIDES
OXYGEN COMPOUNDS
TRANSITION ELEMENTS
550700* - Microbiology