Anammox organism KSU-1 expresses a NirK-type copper-containing nitrite reductase instead of a NirS-type with cytochrome cd1.
Anaerobic ammonium oxidation (anammox) and denitrification are two distinct microbial reactions relevant to the global nitrogen cycle. The proposed initial step of the anammox reactions, reduction of nitrite to nitric oxide, has been postulated to be identical to that in denitrification catalyzed by the dissimilatory nitrite reductase of the cytochrome cd(1)-type. Here, we characterized the copper-containing nitrite reductase homolog encoded by nirK detected in the genome of an anammox bacterium strain KSU-1. We hypothesize that this NirK-type nitrite reductase, rather than a nitrite reductase of the cytochrome cd(1)-type (NirS), is likely to catalyze nitrite reduction in anammox organism KSU-1.
Department of Applied Life Science, Faculty of Biotechnology and Life Science, Sojo University, 4-22-1 Ikeda, Kumamoto 860-0082, Japan. hira@life.sojo-u.ac.jp
Daisuke
D
Hira
Hidehiro
H
Toh
Catharina T
CT
Migita
Hiroki
H
Okubo
Takashi
T
Nishiyama
Masahira
M
Hattori
Kenji
K
Furukawa
Takao
T
Fujii
D000595:Amino Acid Sequence; D000693:Anaerobiosis; D001419:Bacteria / Q000201:enzymology* / Q000235:genetics / Q000378:metabolism; D055162:Biocatalysis; D003300:Copper; D003574:Cytochrome c Group; D003580:Cytochromes / Q000378:metabolism*; D058440:Denitrification; D004926:Escherichia coli / Q000235:genetics; D015870:Gene Expression; D016680:Genome, Bacterial / Q000235:genetics; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009572:Nitrite Reductases / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D009573:Nitrites / Q000378:metabolism; D010084:Oxidation-Reduction; D011487:Protein Conformation; D000644:Quaternary Ammonium Compounds / Q000378:metabolism*; D012689:Sequence Homology, Nucleic Acid
D003574:Cytochrome c Group; D003580:Cytochromes; D009573:Nitrites; D000644:Quaternary Ammonium Compounds; D003300:Copper; C019315:cytochrome cd1; D009572:Nitrite Reductases