Structure of PDB 2a3t Chain A

Receptor sequence

>2a3tA (length=328) Species: 1063 (Cereibacter sphaeroides)

LPRVKHTLVPPPFAHAHEQVAASGPVINEFEMRIIEKEVQLDEDAYLQAM
TFDGSIPGPLMIVHEGDYVELTLINPPENTMPHNIDFHAATGALGGGGLT
LINPGEKVVLRFKATRAGAFVYHCAPGGPMIPWHVVSGMAGCIMVLPRDG
LKDHEGKPVRYDTVYYIGESDHYIPKDEDGTYMRFSDPSEGYEDMVAVMD
TLIPSHIVFNGAVGALTGEGALKAKVGDNVLFVHSQPNRDSRPHLIGGHG
DLVWETGKFHNAPERDLETWFIRGGSAGAALYKFLQPGVYAYVNHNLIEA
VHKGATAHVLVEGEWDNDLMEQVVAPVG

3D structure

• PDB: 2a3t Structures of the oxidized and reduced forms of nitrite reductase from Rhodobacter sphaeroides 2.4.3 at high pH: changes in the interactions of the type 2 copper.
• Chain: A
• Resolution: 1.85 Å

Enzymatic activity

• Catalytic site (original residue number in PDB): H126 D129 H131 H166 C167 H177 M182 H287 E311 T312 H338
• Catalytic site (residue number reindexed from 1): H83 D86 H88 H123 C124 H134 M139 H244 E268 T269 H295
• Enzyme Commision number: 1.7.2.1: nitrite reductase (NO-forming).

Interaction with ligand

Site #	Ligand	Ligand chain	Binding residues on receptor (original residue number in PDB)	Binding residues on receptor (residue number reindexed from 1)	Binding affinity
BS01	CU	A	H126 C167 H177 M182	H83 C124 H134 M139
BS02	CU	A	H131 H166	H88 H123
BS03	MG	A	D220 T224	D177 T181

Gene Ontology

Molecular Function

• GO:0005507 copper ion binding
• GO:0016491 oxidoreductase activity
• GO:0046872 metal ion binding
• GO:0050421 nitrite reductase (NO-forming) activity

Biological Process

• GO:0019333 denitrification pathway
• GO:0042128 nitrate assimilation

Cellular Component

• GO:0042597 periplasmic space

External links

• PDB: RCSB:2a3t, PDBe:2a3t, PDBj:2a3t
• PDBsum: 2a3t
• PubMed: 16131751
• UniProt: Q53239|NIR_CERS5 Copper-containing nitrite reductase (Gene Name=nirK)