Sequence of the gene coding for ammonia monooxygenase in Nitrosomonas europaea.
Nitrosomonas europaea, a chemolithotrophic bacterium, was found to contain two copies of the gene coding for the presumed active site polypeptide of ammonia monooxygenase, the 32-kDa acetylene-binding polypeptide. One copy of this gene was cloned, and its complete nucleotide sequence is presented. Immediately downstream of this gene, in the same operon, is the gene for a 40-kDa polypeptide that copurifies with the ammonia monooxygenase acetylene-binding polypeptide. The sequence of the first 692 nucleotides of this structural gene, coding for about two-thirds of the protein, is presented. These sequences are the first sequences of protein-encoding genes from an ammonia-oxidizing autotrophic nitrifying bacterium. The two protein sequences are not homologous with the sequences of any other monooxygenase. From radioactive labelling of ammonia monooxygenase with [14C]acetylene it was determined that there are 23 nmol of ammonia monooxygenase per g of cells. The kcat of ammonia monooxygenase for NH3 in vivo was calculated to be 20 s-1.
McTavish
H
H
Department of Genetics and Cell Biology, University of Minnesota, St. Paul 55108.
Fuchs
J A
JA
Hooper
A B
AB
D000114:Acetylene / Q000378:metabolism*; D000595:Amino Acid Sequence; D000596:Amino Acids / Q000032:analysis; D001483:Base Sequence; D003001:Cloning, Molecular; D005798:Genes, Bacterial; D008969:Molecular Sequence Data; D009606:Nitrosomonas / Q000201:enzymology*; D009876:Operon; D010088:Oxidoreductases / Q000737:chemistry / Q000235:genetics* / Q000302:isolation & purification
D000596:Amino Acids; D010088:Oxidoreductases; C045582:ammonia monooxygenase; D000114:Acetylene