The Nos (Nitrous Oxide Reductase) Gene Cluster From the Soil Bacterium Achromobacter Cycloclastes: Cloning, Sequence Analysis, and Expression

J Inorg Biochem. 1998 Jul;70(3-4):155-69. doi: 10.1016/s0162-0134(98)10001-6.


The nitrous oxide (N2O) reductase (nos) gene cluster from Achromobacter cycloclastes has been cloned and sequenced. Seven protein coding regions corresponding to nosR, nosZ (structural N2O reductase gene), nosD, nosF, nosY, nosL, and nosX are detected, indicating a genetic organization similar to that of Rhizobium meliloti. To aid homology studies, nosR from R. meliloti has also been sequenced. Comparison of the deduced amino acid sequences with corresponding sequences from other organisms has also allowed structural and functional inferences to be made. The heterologous expression of NosD, NosZ (N2O reductase), and NosL is also reported. A model of the CuA site in N2O reductase, based on the crystal structure of this site in bovine heart cytochrome c oxidase, is presented. The model suggests that a His residue of the CuA domain may be a ligand to the catalytic CuZ site. In addition, the origin of the spectroscopically-observed Cys coordination to CuZ is discussed in terms of the sequence alignment of seven N2O reductases.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Alcaligenes / enzymology*
  • Alcaligenes / genetics*
  • Amino Acid Sequence
  • Animals
  • Bacterial Proteins / chemistry
  • Bacterial Proteins / genetics
  • Bacterial Proteins / metabolism
  • Base Sequence
  • Cattle
  • Cloning, Molecular
  • Electron Transport Complex IV / chemistry
  • Membrane Proteins / genetics
  • Membrane Proteins / metabolism
  • Models, Molecular
  • Molecular Sequence Data
  • Multigene Family*
  • Oxidoreductases / chemistry
  • Oxidoreductases / genetics*
  • Oxidoreductases / metabolism
  • Periplasm / genetics
  • Periplasm / metabolism
  • Protein Conformation
  • RNA, Ribosomal, 16S
  • Recombinant Proteins / chemistry
  • Recombinant Proteins / genetics
  • Recombinant Proteins / metabolism
  • Sequence Analysis
  • Sequence Homology, Amino Acid
  • Sinorhizobium meliloti / enzymology
  • Sinorhizobium meliloti / genetics


  • Bacterial Proteins
  • Membrane Proteins
  • NosX protein, Rhizobium meliloti
  • RNA, Ribosomal, 16S
  • Recombinant Proteins
  • NosR protein, Bacteria
  • Oxidoreductases
  • nitrous oxide reductase
  • nitric-oxide reductase
  • Electron Transport Complex IV