Interaction of the mechanism-based inactivator acetylene with ammonia monooxygenase of Nitrosomonas europaea.
The ammonia monooxygenase (AMO) of Nitrosomonas europaea is a metalloenzyme that catalyses the oxidation of ammonia to hydroxylamine. We have identified histidine 191 of AmoA as the binding site for the oxidized mechanism-based inactivator acetylene. Binding of acetylene changed the molecular mass of His-191 from 155.15 to 197.2 Da (+42.05), providing evidence that acetylene was oxidized to ketene (CH2CO; 42.04 Da) which binds specifically to His-191. It must be assumed that His-191 is part of the acetylene-activating site in AMO or at least directly neighbours this site.
Gilch
Stefan
S
Department of Microbiology, University of Bayreuth, 95447 Bayreuth, Germany.
Vogel
Manja
M
Department of Microbiology, University of Bayreuth, 95447 Bayreuth, Germany.
Lorenz
Matthias W
MW
Department of Animal Ecology, University of Bayreuth, 95447 Bayreuth, Germany.
Meyer
Ortwin
O
Department of Microbiology, University of Bayreuth, 95447 Bayreuth, Germany.
Schmidt
Ingo
I
Department of Microbiology, University of Bayreuth, 95447 Bayreuth, Germany.
D000114:Acetylene / Q000378:metabolism*; D000595:Amino Acid Sequence; D001665:Binding Sites; D002250:Carbon Radioisotopes / Q000378:metabolism; D005030:Ethylenes / Q000378:metabolism; D015964:Gene Expression Regulation, Bacterial; D006639:Histidine / Q000737:chemistry*; D007659:Ketones / Q000378:metabolism; D008969:Molecular Sequence Data; D043370:Nitrosomonas europaea / Q000201:enzymology* / Q000254:growth & development / Q000378:metabolism; D010084:Oxidation-Reduction; D010088:Oxidoreductases / Q000737:chemistry* / Q000378:metabolism*; D010455:Peptides / Q000737:chemistry / Q000378:metabolism
D002250:Carbon Radioisotopes; D005030:Ethylenes; D007659:Ketones; D010455:Peptides; D006639:Histidine; D010088:Oxidoreductases; C045582:ammonia monooxygenase; C008223:ketene; D000114:Acetylene