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Overview for MACiE Entry M0004

Version history

General Information

EC Number: 1.7.2.1 (A member of the Oxidoreductases, Acting on other nitrogenous compounds as donors, With a cytochrome as acceptor)

Enzyme Name: nitrite reductase (NO-forming)

Biological Species: Achromobacter cycloclastes (Bacteria)

Catalytic Chain UniprotKB Accession Codes:

  • P25006 - Copper-containing nitrite reductase

Representative PDB Code: 1nia - THE STRUCTURE OF CU-NITRITE REDUCTASE FROM ACHROMOBACTERCYCLOCLASTES AT FIVE PH VALUES, WITH NITRITE BOUND ANDWITH TYPE II CU DEPLETED (Resolution = 2.50 Å).

Catalytic CATH Codes:

"Other" CATH Codes:

Display structure information

Overall Reaction:

Image of reduced pseudoazurin

Image of proton

Image of nitrous acid

right arrow

Image of oxidised pseudoazurin

Image of water

Image of nitric oxide

reduced pseudoazurin
1bqr
proton
C00080
CHEBI:24636
nitrous acid
C00088
CHEBI:25567
oxidised pseudoazurin
1bqk
water
C00001
CHEBI:15377
nitric oxide
C00533
CHEBI:16480

It is unknown whether this reaction is reversible or not.


View similar reactions


Stepwise Description of the Reaction

Step 1Pseudoazurin donates an electron, through Cu501, Cys136 and His135 to Cu502.
Step 2Cu502 donates the electron to the bound nitrous acid, which collapses to form water, deprotonating His255B, and a Cu-bound NO radical.
Step 3Water displaces the NO radical, and is deprotonated by His255B, to regenerate the enzyme's resting state.

View similar reactions (composite manual annotation)


Catalytic Residues Involved

Type Number Chain Location of Function
Asp 98 A Side Chain
His 135 A Side Chain
Main Chain Carbonyl
Cys 136 A Side Chain
Main Chain Amide
His 255 B Side Chain

Metal Cofactors for M0004

Type Het group Number Chain
copper CU 501 A Overview
copper CU 502 A Overview

References

  1. M. J. Boulanger et al. (2000), J. Biol. Chem., 275, 23957-23964. Catalytic roles for two water bridged residues (Asp-98 and His-255) in the active site of copper-containing nitrite reductase.
    Medline: 10811642
  2. S. V. Antonyuk et al. (2005), Proc. Natl Acad. Sci. USA, 102, 12041-12046. Atomic resolution structures of resting-state, substrate- and product-complexed Cu-nitrite reductase provide insight into catalytic mechanism.
    Medline: 16093314
  3. S. Suzuki et al. (2000), Acc. Chem. Res., 33, 728-735. Metal coordination and mechanism of multicopper nitrite reductase.
    Medline: 11041837
  4. E. I. Tocheva et al. (2004), Science, 304, 867-870. Side-on copper-nitrosyl coordination by nitrite reductase.
    Medline: 15131305
  5. T. Inoue et al. (1999), J. Biol. Chem., 274, 17845-17852. Crystal structure determinations of oxidized and reduced pseudoazurins from Achromobacter cycloclastes. Concerted movement of copper site in redox forms with the rearrangement of hydrogen bond at a remote histidine.
    Medline: 10364229

Homologue information for M0004 (1nia)

CSA Homologues

MACiE Homologues (within the PDB)

MACiE Homologues (within UniprotKB/SwissProt)



Entries with at least one Catalytic CATH code in common (different mechanisms):

MACiE Entry Enzyme Name
EC Number
PDB code CATH code Composite
Reaction Similarity
Catalytic Machinery
Similarity
M0278 plastoquinol-plastocyanin reductase
1.10.99.1
2b3i 2.60.40.420
00.6427Compare

Links to this entry in other databases

Link to EC-PDB-SUM Link to PDB-SUM Link to RCSB PDB Link to PDBe Link to CSA
Link to MetaCyc Link to KEGG Link to BRENDA Link to ExplorENZ

GOA logo
copper ion binding (molecular function)
nitrogen compound metabolic process (biological process)
oxidoreductase activity (molecular function)
nitrate assimilation (biological process)
periplasmic space (cellular component)
metal ion binding (molecular function)
nitrite reductase (NO-forming) activity (molecular function)
oxidation-reduction process (biological process)
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