ID NRFA_ECOLI Reviewed; 478 AA. AC P0ABK9; P32050; Q2M6N4; DT 08-NOV-2005, integrated into UniProtKB/Swiss-Prot. DT 08-NOV-2005, sequence version 1. DT 03-MAY-2023, entry version 136. DE RecName: Full=Cytochrome c-552 {ECO:0000303|PubMed:7934939}; DE EC=1.7.2.2 {ECO:0000269|PubMed:11863430, ECO:0000269|PubMed:18311941, ECO:0000269|PubMed:20629638, ECO:0000269|PubMed:9593308}; DE AltName: Full=Ammonia-forming cytochrome c nitrite reductase; DE Short=Cytochrome c nitrite reductase {ECO:0000303|PubMed:11863430}; DE Flags: Precursor; GN Name=nrfA; OrderedLocusNames=b4070, JW4031; OS Escherichia coli (strain K12). OC Bacteria; Pseudomonadota; Gammaproteobacteria; Enterobacterales; OC Enterobacteriaceae; Escherichia. OX NCBI_TaxID=83333; RN [1] RP NUCLEOTIDE SEQUENCE [GENOMIC DNA], PROTEIN SEQUENCE OF 27-42 AND 150-167, RP FUNCTION, SUBCELLULAR LOCATION, COFACTOR, AND INDUCTION. RC STRAIN=K12; RX PubMed=7934939; DOI=10.1111/j.1365-2958.1993.tb01255.x; RA Darwin A., Hussain H.A., Griffiths L., Grove J., Sambongi Y., Busby S., RA Cole J.; RT "Regulation and sequence of the structural gene for cytochrome c552 from RT Escherichia coli: not a hexahaem but a 50 kDa tetrahaem nitrite RT reductase."; RL Mol. Microbiol. 9:1255-1265(1993). RN [2] RP NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA]. RC STRAIN=K12 / MG1655 / ATCC 47076; RX PubMed=8265357; DOI=10.1093/nar/21.23.5408; RA Blattner F.R., Burland V.D., Plunkett G. III, Sofia H.J., Daniels D.L.; RT "Analysis of the Escherichia coli genome. IV. DNA sequence of the region RT from 89.2 to 92.8 minutes."; RL Nucleic Acids Res. 21:5408-5417(1993). RN [3] RP NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA]. RC STRAIN=K12 / MG1655 / ATCC 47076; RX PubMed=9278503; DOI=10.1126/science.277.5331.1453; RA Blattner F.R., Plunkett G. III, Bloch C.A., Perna N.T., Burland V., RA Riley M., Collado-Vides J., Glasner J.D., Rode C.K., Mayhew G.F., RA Gregor J., Davis N.W., Kirkpatrick H.A., Goeden M.A., Rose D.J., Mau B., RA Shao Y.; RT "The complete genome sequence of Escherichia coli K-12."; RL Science 277:1453-1462(1997). RN [4] RP NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA]. RC STRAIN=K12 / W3110 / ATCC 27325 / DSM 5911; RX PubMed=16738553; DOI=10.1038/msb4100049; RA Hayashi K., Morooka N., Yamamoto Y., Fujita K., Isono K., Choi S., RA Ohtsubo E., Baba T., Wanner B.L., Mori H., Horiuchi T.; RT "Highly accurate genome sequences of Escherichia coli K-12 strains MG1655 RT and W3110."; RL Mol. Syst. Biol. 2:E1-E5(2006). RN [5] RP CHARACTERIZATION AS A CYTOCHROME C. RX PubMed=8039676; DOI=10.1111/j.1574-6968.1994.tb06872.x; RA Iobbi-Nivol C., Crooke H., Griffiths L., Grov J., Hussain H., Pommier J., RA Mejean V., Cole J.A.; RT "A reassessment of the range of c-type cytochromes synthesized by RT Escherichia coli K-12."; RL FEMS Microbiol. Lett. 119:89-94(1994). RN [6] RP FUNCTION, CATALYTIC ACTIVITY, HEME-BINDING, COFACTOR, SUBCELLULAR LOCATION, RP MASS SPECTROMETRY, AND MUTAGENESIS OF LYS-126. RC STRAIN=K12 / JCB7120; RX PubMed=9593308; DOI=10.1046/j.1365-2958.1998.00792.x; RA Eaves D.J., Grove J., Staudenmann W., James P., Poole R.K., White S.A., RA Griffiths I., Cole J.A.; RT "Involvement of products of the nrfEFG genes in the covalent attachment of RT haem c to a novel cysteine-lysine motif in the cytochrome c552 nitrite RT reductase from Escherichia coli."; RL Mol. Microbiol. 28:205-216(1998). RN [7] RP X-RAY CRYSTALLOGRAPHY (2.5 ANGSTROMS) IN COMPLEX WITH CALCIUM AND HEME, RP CATALYTIC ACTIVITY, BIOPHYSICOCHEMICAL PROPERTIES, COFACTOR, SUBCELLULAR RP LOCATION, MAGNETIC CIRCULAR DICHROISM, AND EPR SPECTROSCOPY. RX PubMed=11863430; DOI=10.1021/bi015765d; RA Bamford V.A., Angove H.C., Seward H.E., Thomson A.J., Cole J.A., Butt J.N., RA Hemmings A.M., Richardson D.J.; RT "Structure and spectroscopy of the periplasmic cytochrome c nitrite RT reductase from Escherichia coli."; RL Biochemistry 41:2921-2931(2002). RN [8] {ECO:0007744|PDB:2RDZ, ECO:0007744|PDB:2RF7} RP X-RAY CRYSTALLOGRAPHY (1.74 ANGSTROMS) OF 27-478 IN COMPLEX WITH CALCIUM RP AND HEME, CATALYTIC ACTIVITY, COFACTOR, AND MUTAGENESIS OF GLN-263. RX PubMed=18311941; DOI=10.1021/bi702175w; RA Clarke T.A., Kemp G.L., Van Wonderen J.H., Doyle R.M., Cole J.A., RA Tovell N., Cheesman M.R., Butt J.N., Richardson D.J., Hemmings A.M.; RT "Role of a conserved glutamine residue in tuning the catalytic activity of RT Escherichia coli cytochrome c nitrite reductase."; RL Biochemistry 47:3789-3799(2008). RN [9] {ECO:0007744|PDB:3L1T} RP X-RAY CRYSTALLOGRAPHY (2.30 ANGSTROMS) OF 27-478 IN COMPLEX WITH CALCIUM; RP HEME AND HYDROGENSULFITE, CATALYTIC ACTIVITY, FUNCTION, BIOPHYSICOCHEMICAL RP PROPERTIES, ACTIVITY REGULATION, AND COFACTOR. RX PubMed=20629638; DOI=10.1042/bj20100866; RA Kemp G.L., Clarke T.A., Marritt S.J., Lockwood C., Poock S.R., RA Hemmings A.M., Richardson D.J., Cheesman M.R., Butt J.N.; RT "Kinetic and thermodynamic resolution of the interactions between sulfite RT and the pentahaem cytochrome NrfA from Escherichia coli."; RL Biochem. J. 431:73-80(2010). RN [10] {ECO:0007744|PDB:3TOR} RP X-RAY CRYSTALLOGRAPHY (2.00 ANGSTROMS) OF 27-478 IN COMPLEX WITH CALCIUM RP AND HEME, AND COFACTOR. RX PubMed=22103542; DOI=10.1042/bst20110731; RA Lockwood C.W., Clarke T.A., Butt J.N., Hemmings A.M., Richardson D.J.; RT "Characterization of the active site and calcium binding in cytochrome c RT nitrite reductases."; RL Biochem. Soc. Trans. 39:1871-1875(2011). CC -!- FUNCTION: Catalyzes the reduction of nitrite to ammonia, consuming six CC electrons in the process (PubMed:9593308, PubMed:11863430, CC PubMed:18311941, PubMed:20629638). Has very low activity toward CC hydroxylamine (PubMed:11863430). Has even lower activity toward sulfite CC (PubMed:20629638). Sulfite reductase activity is maximal at neutral pH CC (By similarity). {ECO:0000250|UniProtKB:L0DSL2, CC ECO:0000269|PubMed:11863430, ECO:0000269|PubMed:18311941, CC ECO:0000269|PubMed:20629638, ECO:0000269|PubMed:9593308, CC ECO:0000305|PubMed:7934939}. CC -!- CATALYTIC ACTIVITY: CC Reaction=6 Fe(III)-[cytochrome c] + 2 H2O + NH4(+) = 6 Fe(II)- CC [cytochrome c] + 8 H(+) + nitrite; Xref=Rhea:RHEA:13089, Rhea:RHEA- CC COMP:10350, Rhea:RHEA-COMP:14399, ChEBI:CHEBI:15377, CC ChEBI:CHEBI:15378, ChEBI:CHEBI:16301, ChEBI:CHEBI:28938, CC ChEBI:CHEBI:29033, ChEBI:CHEBI:29034; EC=1.7.2.2; CC Evidence={ECO:0000269|PubMed:11863430, ECO:0000269|PubMed:18311941, CC ECO:0000269|PubMed:20629638, ECO:0000269|PubMed:9593308}; CC -!- COFACTOR: CC Name=Ca(2+); Xref=ChEBI:CHEBI:29108; CC Evidence={ECO:0000269|PubMed:11863430, ECO:0000269|PubMed:18311941, CC ECO:0000269|PubMed:20629638, ECO:0000269|PubMed:22103542}; CC Note=Binds 1 Ca(2+) ion per monomer. {ECO:0000269|PubMed:11863430, CC ECO:0000269|PubMed:18311941, ECO:0000269|PubMed:20629638, CC ECO:0000269|PubMed:22103542}; CC -!- COFACTOR: CC Name=heme c; Xref=ChEBI:CHEBI:61717; CC Evidence={ECO:0000269|PubMed:11863430, ECO:0000269|PubMed:18311941, CC ECO:0000269|PubMed:20629638, ECO:0000269|PubMed:22103542, CC ECO:0000269|PubMed:7934939, ECO:0000269|PubMed:9593308}; CC Note=Binds 5 heme c groups covalently per monomer. CC {ECO:0000269|PubMed:11863430, ECO:0000269|PubMed:18311941, CC ECO:0000269|PubMed:20629638, ECO:0000269|PubMed:22103542}; CC -!- ACTIVITY REGULATION: Subject to competitive inhibition by sulfite. CC {ECO:0000269|PubMed:20629638}. CC -!- BIOPHYSICOCHEMICAL PROPERTIES: CC Kinetic parameters: CC KM=28 uM for nitrite {ECO:0000269|PubMed:11863430}; CC KM=30 uM for nitrite {ECO:0000269|PubMed:18311941}; CC KM=22 uM for nitrite {ECO:0000269|PubMed:20629638}; CC KM=70 uM for sulfite {ECO:0000269|PubMed:20629638}; CC KM=30 mM for hydroxylamine {ECO:0000269|PubMed:11863430}; CC -!- PATHWAY: Nitrogen metabolism; nitrate reduction (assimilation). CC {ECO:0000305|PubMed:7934939}. CC -!- SUBUNIT: Homodimer (PubMed:11863430, PubMed:18311941). Component of a CC membrane-associated heterooligomeric complex (Probable). CC {ECO:0000269|PubMed:11863430, ECO:0000269|PubMed:18311941, CC ECO:0000305}. CC -!- SUBCELLULAR LOCATION: Periplasm {ECO:0000269|PubMed:11863430, CC ECO:0000269|PubMed:7934939, ECO:0000269|PubMed:9593308}. CC -!- INDUCTION: Full induction attained in the presence of nitrite. Subject CC to glucose and nitrate repression. {ECO:0000269|PubMed:7934939}. CC -!- MASS SPECTROMETRY: Mass=53590; Method=MALDI; CC Evidence={ECO:0000269|PubMed:9593308}; CC -!- SIMILARITY: Belongs to the cytochrome c-552 family. {ECO:0000305}. CC --------------------------------------------------------------------------- CC Copyrighted by the UniProt Consortium, see https://www.uniprot.org/terms CC Distributed under the Creative Commons Attribution (CC BY 4.0) License CC --------------------------------------------------------------------------- DR EMBL; X72298; CAA51048.1; -; Genomic_DNA. DR EMBL; U00006; AAC43164.1; -; Genomic_DNA. DR EMBL; U00096; AAC77040.1; -; Genomic_DNA. DR EMBL; AP009048; BAE78072.1; -; Genomic_DNA. DR PIR; S39590; S39590. DR RefSeq; NP_418494.1; NC_000913.3. DR RefSeq; WP_000196875.1; NZ_STEB01000014.1. DR PDB; 1GU6; X-ray; 2.50 A; A/C/E/G=27-478. DR PDB; 2RDZ; X-ray; 1.74 A; A/B/C/D=27-478. DR PDB; 2RF7; X-ray; 2.04 A; A/B/C/D=37-477. DR PDB; 3L1T; X-ray; 2.30 A; A/B/C/D=27-478. DR PDB; 3TOR; X-ray; 2.00 A; A/B/C/D=27-478. DR PDB; 4WJY; X-ray; 2.15 A; A/B=27-478. DR PDBsum; 1GU6; -. DR PDBsum; 2RDZ; -. DR PDBsum; 2RF7; -. DR PDBsum; 3L1T; -. DR PDBsum; 3TOR; -. DR PDBsum; 4WJY; -. DR AlphaFoldDB; P0ABK9; -. DR SMR; P0ABK9; -. DR BioGRID; 4259405; 27. DR DIP; DIP-36021N; -. DR IntAct; P0ABK9; 3. DR STRING; 511145.b4070; -. DR DrugBank; DB03317; Ferroheme C. DR TCDB; 5.A.3.5.3; the prokaryotic molybdopterin-containing oxidoreductase (pmo) family. DR jPOST; P0ABK9; -. DR PaxDb; P0ABK9; -. DR EnsemblBacteria; AAC77040; AAC77040; b4070. DR EnsemblBacteria; BAE78072; BAE78072; BAE78072. DR GeneID; 66672014; -. DR GeneID; 75169593; -. DR GeneID; 948571; -. DR KEGG; ecj:JW4031; -. DR KEGG; eco:b4070; -. DR PATRIC; fig|1411691.4.peg.2634; -. DR EchoBASE; EB1729; -. DR eggNOG; COG3303; Bacteria. DR HOGENOM; CLU_035040_1_0_6; -. DR InParanoid; P0ABK9; -. DR OMA; EMVILWA; -. DR OrthoDB; 9780421at2; -. DR PhylomeDB; P0ABK9; -. DR BioCyc; EcoCyc:CYTOCHROMEC552-MON; -. DR BioCyc; MetaCyc:CYTOCHROMEC552-MON; -. DR BRENDA; 1.7.2.2; 2026. DR SABIO-RK; P0ABK9; -. DR UniPathway; UPA00653; -. DR EvolutionaryTrace; P0ABK9; -. DR PRO; PR:P0ABK9; -. DR Proteomes; UP000000318; Chromosome. DR Proteomes; UP000000625; Chromosome. DR GO; GO:0030288; C:outer membrane-bounded periplasmic space; IDA:EcoCyc. DR GO; GO:0005509; F:calcium ion binding; IEA:UniProtKB-UniRule. DR GO; GO:0020037; F:heme binding; IDA:EcoCyc. DR GO; GO:0005506; F:iron ion binding; IEA:UniProtKB-UniRule. DR GO; GO:0016966; F:nitric oxide reductase activity; IDA:CACAO. DR GO; GO:0042279; F:nitrite reductase (cytochrome, ammonia-forming) activity; IDA:EcoCyc. DR GO; GO:0019645; P:anaerobic electron transport chain; IMP:EcoCyc. DR GO; GO:0042128; P:nitrate assimilation; IEA:UniProtKB-UniPathway. DR CDD; cd00548; NrfA-like; 1. DR Gene3D; 1.20.140.10; Butyryl-CoA Dehydrogenase, subunit A, domain 3; 1. DR HAMAP; MF_01182; Cytochrom_C552; 1. DR InterPro; IPR003321; Cyt_c552. DR InterPro; IPR017570; Cyt_c_NO2Rdtase_formate-dep. DR InterPro; IPR036280; Multihaem_cyt_sf. DR PANTHER; PTHR30633:SF0; CYTOCHROME C-552; 1. DR PANTHER; PTHR30633; CYTOCHROME C-552 RESPIRATORY NITRITE REDUCTASE; 1. DR Pfam; PF02335; Cytochrom_C552; 1. DR PIRSF; PIRSF000243; Cyt_c552; 1. DR SUPFAM; SSF48695; Multiheme cytochromes; 1. DR TIGRFAMs; TIGR03152; cyto_c552_HCOOH; 1. DR PROSITE; PS51008; MULTIHEME_CYTC; 1. PE 1: Evidence at protein level; KW 3D-structure; Calcium; Direct protein sequencing; Electron transport; Heme; KW Iron; Metal-binding; Oxidoreductase; Periplasm; Reference proteome; Signal; KW Transport. FT SIGNAL 1..26 FT /evidence="ECO:0000269|PubMed:7934939" FT CHAIN 27..478 FT /note="Cytochrome c-552" FT /id="PRO_0000006578" FT BINDING 94 FT /ligand="heme c" FT /ligand_id="ChEBI:CHEBI:61717" FT /ligand_label="3" FT /ligand_part="Fe" FT /ligand_part_id="ChEBI:CHEBI:18248" FT /note="axial binding residue" FT /evidence="ECO:0007744|PDB:1GU6, ECO:0007744|PDB:2RDZ, FT ECO:0007744|PDB:2RF7, ECO:0007744|PDB:3L1T, FT ECO:0007744|PDB:3TOR" FT BINDING 122 FT /ligand="heme c" FT /ligand_id="ChEBI:CHEBI:61717" FT /ligand_label="1" FT /note="covalent" FT /evidence="ECO:0007744|PDB:1GU6, ECO:0007744|PDB:2RDZ, FT ECO:0007744|PDB:2RF7, ECO:0007744|PDB:3L1T, FT ECO:0007744|PDB:3TOR" FT BINDING 125 FT /ligand="heme c" FT /ligand_id="ChEBI:CHEBI:61717" FT /ligand_label="1" FT /note="covalent" FT /evidence="ECO:0007744|PDB:1GU6, ECO:0007744|PDB:2RDZ, FT ECO:0007744|PDB:2RF7, ECO:0007744|PDB:3L1T, FT ECO:0007744|PDB:3TOR" FT BINDING 126 FT /ligand="heme c" FT /ligand_id="ChEBI:CHEBI:61717" FT /ligand_label="1" FT /ligand_part="Fe" FT /ligand_part_id="ChEBI:CHEBI:18248" FT /note="axial binding residue" FT /evidence="ECO:0007744|PDB:1GU6, ECO:0007744|PDB:2RDZ, FT ECO:0007744|PDB:2RF7, ECO:0007744|PDB:3L1T, FT ECO:0007744|PDB:3TOR" FT BINDING 160 FT /ligand="heme c" FT /ligand_id="ChEBI:CHEBI:61717" FT /ligand_label="2" FT /note="covalent" FT /evidence="ECO:0007744|PDB:1GU6, ECO:0007744|PDB:2RDZ, FT ECO:0007744|PDB:2RF7, ECO:0007744|PDB:3L1T, FT ECO:0007744|PDB:3TOR" FT BINDING 163 FT /ligand="heme c" FT /ligand_id="ChEBI:CHEBI:61717" FT /ligand_label="2" FT /note="covalent" FT /evidence="ECO:0007744|PDB:1GU6, ECO:0007744|PDB:2RDZ, FT ECO:0007744|PDB:2RF7, ECO:0007744|PDB:3L1T, FT ECO:0007744|PDB:3TOR" FT BINDING 164 FT /ligand="heme c" FT /ligand_id="ChEBI:CHEBI:61717" FT /ligand_label="2" FT /ligand_part="Fe" FT /ligand_part_id="ChEBI:CHEBI:18248" FT /note="axial binding residue" FT /evidence="ECO:0007744|PDB:1GU6, ECO:0007744|PDB:2RDZ, FT ECO:0007744|PDB:2RF7, ECO:0007744|PDB:3L1T, FT ECO:0007744|PDB:3TOR" FT BINDING 209 FT /ligand="heme c" FT /ligand_id="ChEBI:CHEBI:61717" FT /ligand_label="3" FT /note="covalent" FT /evidence="ECO:0007744|PDB:1GU6, ECO:0007744|PDB:2RDZ, FT ECO:0007744|PDB:2RF7, ECO:0007744|PDB:3L1T, FT ECO:0007744|PDB:3TOR" FT BINDING 212 FT /ligand="heme c" FT /ligand_id="ChEBI:CHEBI:61717" FT /ligand_label="3" FT /note="covalent" FT /evidence="ECO:0007744|PDB:1GU6, ECO:0007744|PDB:2RDZ, FT ECO:0007744|PDB:2RF7, ECO:0007744|PDB:3L1T, FT ECO:0007744|PDB:3TOR" FT BINDING 213 FT /ligand="heme c" FT /ligand_id="ChEBI:CHEBI:61717" FT /ligand_label="3" FT /ligand_part="Fe" FT /ligand_part_id="ChEBI:CHEBI:18248" FT /note="axial binding residue" FT /evidence="ECO:0007744|PDB:1GU6, ECO:0007744|PDB:2RDZ, FT ECO:0007744|PDB:2RF7, ECO:0007744|PDB:3L1T, FT ECO:0007744|PDB:3TOR" FT BINDING 215 FT /ligand="Ca(2+)" FT /ligand_id="ChEBI:CHEBI:29108" FT /evidence="ECO:0007744|PDB:1GU6, ECO:0007744|PDB:2RDZ, FT ECO:0007744|PDB:2RF7, ECO:0007744|PDB:3L1T, FT ECO:0007744|PDB:3TOR" FT BINDING 216 FT /ligand="Ca(2+)" FT /ligand_id="ChEBI:CHEBI:29108" FT /evidence="ECO:0007744|PDB:1GU6, ECO:0007744|PDB:2RDZ, FT ECO:0007744|PDB:2RF7, ECO:0007744|PDB:3L1T, FT ECO:0007744|PDB:3TOR" FT BINDING 216 FT /ligand="substrate" FT /evidence="ECO:0000305" FT BINDING 261 FT /ligand="Ca(2+)" FT /ligand_id="ChEBI:CHEBI:29108" FT /evidence="ECO:0007744|PDB:1GU6, ECO:0007744|PDB:2RDZ, FT ECO:0007744|PDB:2RF7, ECO:0007744|PDB:3L1T, FT ECO:0007744|PDB:3TOR" FT BINDING 263 FT /ligand="Ca(2+)" FT /ligand_id="ChEBI:CHEBI:29108" FT /evidence="ECO:0007744|PDB:1GU6, ECO:0007744|PDB:2RDZ, FT ECO:0007744|PDB:3L1T, ECO:0007744|PDB:3TOR" FT BINDING 264 FT /ligand="substrate" FT /evidence="ECO:0000305" FT BINDING 275 FT /ligand="heme c" FT /ligand_id="ChEBI:CHEBI:61717" FT /ligand_label="5" FT /ligand_part="Fe" FT /ligand_part_id="ChEBI:CHEBI:18248" FT /note="axial binding residue" FT /evidence="ECO:0007744|PDB:1GU6, ECO:0007744|PDB:2RDZ, FT ECO:0007744|PDB:2RF7, ECO:0007744|PDB:3L1T, FT ECO:0007744|PDB:3TOR" FT BINDING 282 FT /ligand="heme c" FT /ligand_id="ChEBI:CHEBI:61717" FT /ligand_label="4" FT /note="covalent" FT /evidence="ECO:0007744|PDB:1GU6, ECO:0007744|PDB:2RDZ, FT ECO:0007744|PDB:2RF7, ECO:0007744|PDB:3L1T, FT ECO:0007744|PDB:3TOR" FT BINDING 285 FT /ligand="heme c" FT /ligand_id="ChEBI:CHEBI:61717" FT /ligand_label="4" FT /note="covalent" FT /evidence="ECO:0007744|PDB:1GU6, ECO:0007744|PDB:2RDZ, FT ECO:0007744|PDB:2RF7" FT BINDING 286 FT /ligand="heme c" FT /ligand_id="ChEBI:CHEBI:61717" FT /ligand_label="4" FT /ligand_part="Fe" FT /ligand_part_id="ChEBI:CHEBI:18248" FT /note="axial binding residue" FT /evidence="ECO:0007744|PDB:1GU6, ECO:0007744|PDB:2RDZ, FT ECO:0007744|PDB:2RF7, ECO:0007744|PDB:3L1T, FT ECO:0007744|PDB:3TOR" FT BINDING 301 FT /ligand="heme c" FT /ligand_id="ChEBI:CHEBI:61717" FT /ligand_label="2" FT /ligand_part="Fe" FT /ligand_part_id="ChEBI:CHEBI:18248" FT /note="axial binding residue" FT /evidence="ECO:0007744|PDB:1GU6, ECO:0007744|PDB:2RDZ, FT ECO:0007744|PDB:2RF7, ECO:0007744|PDB:3L1T, FT ECO:0007744|PDB:3TOR" FT BINDING 314 FT /ligand="heme c" FT /ligand_id="ChEBI:CHEBI:61717" FT /ligand_label="5" FT /note="covalent" FT /evidence="ECO:0007744|PDB:1GU6, ECO:0007744|PDB:2RDZ, FT ECO:0007744|PDB:2RF7, ECO:0007744|PDB:3L1T, FT ECO:0007744|PDB:3TOR" FT BINDING 317 FT /ligand="heme c" FT /ligand_id="ChEBI:CHEBI:61717" FT /ligand_label="5" FT /note="covalent" FT /evidence="ECO:0007744|PDB:1GU6, ECO:0007744|PDB:2RDZ, FT ECO:0007744|PDB:2RF7" FT BINDING 318 FT /ligand="heme c" FT /ligand_id="ChEBI:CHEBI:61717" FT /ligand_label="5" FT /ligand_part="Fe" FT /ligand_part_id="ChEBI:CHEBI:18248" FT /note="axial binding residue" FT /evidence="ECO:0007744|PDB:1GU6, ECO:0007744|PDB:2RDZ, FT ECO:0007744|PDB:2RF7, ECO:0007744|PDB:3L1T, FT ECO:0007744|PDB:3TOR" FT BINDING 393 FT /ligand="heme c" FT /ligand_id="ChEBI:CHEBI:61717" FT /ligand_label="4" FT /ligand_part="Fe" FT /ligand_part_id="ChEBI:CHEBI:18248" FT /note="axial binding residue" FT /evidence="ECO:0007744|PDB:1GU6, ECO:0007744|PDB:2RDZ, FT ECO:0007744|PDB:2RF7, ECO:0007744|PDB:3L1T, FT ECO:0007744|PDB:3TOR" FT MUTAGEN 126 FT /note="K->H,I,L: Almost complete loss of nitrite reductase FT activity." FT /evidence="ECO:0000269|PubMed:9593308" FT MUTAGEN 263 FT /note="Q->E: Increases affinity for nitrite without FT changing Vmax." FT /evidence="ECO:0000269|PubMed:18311941" FT HELIX 42..45 FT /evidence="ECO:0007829|PDB:2RDZ" FT TURN 46..48 FT /evidence="ECO:0007829|PDB:2RDZ" FT HELIX 50..57 FT /evidence="ECO:0007829|PDB:2RDZ" FT HELIX 58..61 FT /evidence="ECO:0007829|PDB:2RDZ" FT HELIX 68..71 FT /evidence="ECO:0007829|PDB:2RDZ" FT HELIX 74..78 FT /evidence="ECO:0007829|PDB:2RDZ" FT TURN 79..81 FT /evidence="ECO:0007829|PDB:2RDZ" FT HELIX 83..85 FT /evidence="ECO:0007829|PDB:2RDZ" FT HELIX 94..96 FT /evidence="ECO:0007829|PDB:2RDZ" FT HELIX 97..103 FT /evidence="ECO:0007829|PDB:2RDZ" FT HELIX 105..107 FT /evidence="ECO:0007829|PDB:2RDZ" FT STRAND 116..119 FT /evidence="ECO:0007829|PDB:2RDZ" FT HELIX 120..123 FT /evidence="ECO:0007829|PDB:2RDZ" FT TURN 124..126 FT /evidence="ECO:0007829|PDB:2RDZ" FT HELIX 129..137 FT /evidence="ECO:0007829|PDB:2RDZ" FT HELIX 139..143 FT /evidence="ECO:0007829|PDB:2RDZ" FT STRAND 144..146 FT /evidence="ECO:0007829|PDB:2RDZ" FT HELIX 147..150 FT /evidence="ECO:0007829|PDB:2RDZ" FT TURN 151..153 FT /evidence="ECO:0007829|PDB:2RDZ" FT HELIX 160..163 FT /evidence="ECO:0007829|PDB:2RDZ" FT HELIX 169..172 FT /evidence="ECO:0007829|PDB:2RDZ" FT HELIX 183..191 FT /evidence="ECO:0007829|PDB:2RDZ" FT HELIX 196..198 FT /evidence="ECO:0007829|PDB:2RDZ" FT HELIX 201..209 FT /evidence="ECO:0007829|PDB:2RDZ" FT TURN 210..212 FT /evidence="ECO:0007829|PDB:2RDZ" FT STRAND 217..219 FT /evidence="ECO:0007829|PDB:2RDZ" FT TURN 220..223 FT /evidence="ECO:0007829|PDB:2RDZ" FT STRAND 224..226 FT /evidence="ECO:0007829|PDB:2RDZ" FT HELIX 235..244 FT /evidence="ECO:0007829|PDB:2RDZ" FT STRAND 249..251 FT /evidence="ECO:0007829|PDB:2RDZ" FT TURN 253..255 FT /evidence="ECO:0007829|PDB:2RDZ" FT HELIX 266..272 FT /evidence="ECO:0007829|PDB:2RDZ" FT HELIX 274..277 FT /evidence="ECO:0007829|PDB:2RDZ" FT HELIX 282..286 FT /evidence="ECO:0007829|PDB:2RDZ" FT STRAND 289..291 FT /evidence="ECO:0007829|PDB:2RDZ" FT STRAND 297..299 FT /evidence="ECO:0007829|PDB:2RDZ" FT HELIX 306..312 FT /evidence="ECO:0007829|PDB:2RDZ" FT HELIX 314..316 FT /evidence="ECO:0007829|PDB:2RDZ" FT HELIX 322..359 FT /evidence="ECO:0007829|PDB:2RDZ" FT HELIX 364..385 FT /evidence="ECO:0007829|PDB:2RDZ" FT HELIX 390..393 FT /evidence="ECO:0007829|PDB:2RDZ" FT HELIX 395..422 FT /evidence="ECO:0007829|PDB:2RDZ" FT HELIX 437..443 FT /evidence="ECO:0007829|PDB:2RDZ" FT HELIX 448..472 FT /evidence="ECO:0007829|PDB:2RDZ" SQ SEQUENCE 478 AA; 53703 MW; F965E986412A0456 CRC64; MTRIKINARR IFSLLIPFFF FTSVHAEQTA APAKPVTVEA KNETFAPQHP DQYLSWKATS EQSERVDALA EDPRLVILWA GYPFSRDYNK PRGHAFAVTD VRETLRTGAP KNAEDGPLPM ACWSCKSPDV ARLIQKDGED GYFHGKWARG GPEIVNNLGC ADCHNTASPE FAKGKPELTL SRPYAARAME AIGKPFEKAG RFDQQSMVCG QCHVEYYFDG KNKAVKFPWD DGMKVENMEQ YYDKIAFSDW TNSLSKTPML KAQHPEYETW TAGIHGKNNV TCIDCHMPKV QNAEGKLYTD HKIGNPFDNF AQTCANCHTQ DKAALQKVVA ERKQSINDLK IKVEDQLVHA HFEAKAALDA GATEAEMKPI QDDIRHAQWR WDLAIASHGI HMHAPEEGLR MLGTAMDKAA DARTKLARLL ATKGITHEIQ IPDISTKEKA QQAIGLNMEQ IKAEKQDFIK TVIPQWEEQA RKNGLLSQ //