Nucleotide sequence, organisation and structural analysis of the products of genes in the nirB-cysG region of the Escherichia coli K-12 chromosome

Eur J Biochem. 1990 Jul 31;191(2):315-23. doi: 10.1111/j.1432-1033.1990.tb19125.x.


The DNA sequence and derived amino-acid sequence of a 5618-base region in the 74-min area of the Escherichia coli chromosome has been determined in order to locate the structural gene, nirB, for the NADH-dependent nitrite reductase and a gene, cysG, required for the synthesis of the sirohaem prosthetic group. Three additional open reading frames, nirD, nirE and nirC, were found between nirB and cysG. Potential binding sites on the NirB protein for NADH and FAD, as well as conserved central core and interface domains, were deduced by comparing the derived amino-acid sequence with those of database proteins. A directly repeated sequence, which includes the motif -Cys-Xaa-Xaa-Cys-, is suggested as the binding site for either one [4Fe-4S] or two [2Fe-2S] clusters. The nirD gene potentially encodes a soluble, cytoplasmic protein of unknown function. No significant similarities were found between the derived amino-acid sequence of NirD and either NirB or any other protein in the database. If the nirE open reading frame is translated, it would encode a 33-amino-acid peptide of unknown function which includes 8 phenylalanyl residues. The product of the nirC gene is a highly hydrophobic protein with regions of amino-acid sequence similar to cytochrome oxidase polypeptide 1.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Bacterial Proteins / genetics*
  • Base Sequence
  • Chromosomes, Bacterial / analysis*
  • Escherichia coli / genetics*
  • Escherichia coli / ultrastructure
  • Gene Expression*
  • Genes, Bacterial*
  • Molecular Sequence Data
  • Nitrate Reductase
  • Nitrate Reductases / genetics
  • Promoter Regions, Genetic
  • Repetitive Sequences, Nucleic Acid


  • Bacterial Proteins
  • Nitrate Reductases
  • Nitrate Reductase

Associated data

  • GENBANK/X14202