Sequence of the gene coding for ammonia monooxygenase in Nitrosomonas europaea

作者：Hugh McTavish, James A. Fuchs, Alan B. Hooper · 发表于：Journal of Bacteriology · 年份：1993 · DOI：10.1128/jb.175.8.2436-2444.1993 · 被引用次数：288 · 研究领域：Microbial Fuel Cells and Bioremediation、Wastewater Treatment and Nitrogen Removal、Microbial Community Ecology and Physiology

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.