Structure of PDB 3ir6 Chain A

Receptor sequence

>3ir6A (length=1233) Species: 83333 (Escherichia coli K-12)

SKFLDRFRQKGETFADGHGQLLNTNRDWEDGYRQRWQHDKIVRSTSCSWK
IYVKNGLVTWETQQTDYPRTRPDLPNHEPRGCPRGASYSWYLYSANRLKY
PMMRKRLMKMWREAKALHSDPVEAWASIIEDADKAKSFKQARGRGGFVRS
SWQEVNELIAASNVYTIKNYGPDRVAGFSPIPAMSMVSYASGARYLSLIG
GTCLSFYDWYCDLPPASPQTWGEQTDVPESADWYNSSYIIAWGSNVPQTR
TPDAHFFTEVRYKGTKTVAVTPDYAEIAKLCDLWLAPKQGTDAAMALAMG
HVMLREFHLDNPSQYFTDYVRRYTDMPMLVMLEERDGYYAAGRMLRAADL
VDALGQENNPEWKTVAFNTNGEMVAPNGSIGFRWGEKGKWNLEQRDGKTG
EETELQLSLLGSQDEIAEVGFPYFGGDGTEHFNKVELENVLLHKLPVKRL
QLADGSTALVTTVYDLTLANYGLERGLNDVNCATSYDDVKAYTPAWAEQI
TGVSRSQIIRIAREFADNADKTHGRSMIIVGAGLNHWYHLDMNYRGLINM
LIFCGCVGQSGGGWAHYVGEKLRPQTGWQPLAFALDWQRPARHMNSTSYF
YNHSSQWRYETVTAEELLSPMADKSRYTGHLIDFNVRAERMGWLPSAPQL
GTNPLTIAGEAEKAGMNPVDYTVKSLKEGSIRFAAEQPENGKNHPRNLFI
WRSNLLGSSGKGHEFMLKYLLGTEHGIQGKDLGQQGGVKPEEVDWQDNGL
EGKLDLVVTLDFRLSSTCLYSDIILPTATWYEKDDMNTSDMHPFIHPLSA
AVDPAWEAKSDWEIYKAIAKKFSEVCVGHLGKETDIVTLPIQHDSAAELA
QPLDVKDWKKGECDLIPGKTAPHIMVVERDYPATYERFTSIGPLMEKIGN
GGKGIAWNTQSEMDLLRKLNYTKAEGPAKGQPMLNTAIDAAEMILTLAPE
TNGQVAVKAWAALSEFTGRDHTHLALNKEDEKIRFRDIQAQPRKIISSPT
WSGLEDEHVSYNAGYTNVHELIPWRTLSGRQQLYQDHQWMRDFGESLLVY
RPPIDTRSVKEVIGQKSNGNQEKALNFLTPHQKWGIHSTYSDNLLMLTLG
RGGPVVWLSEADAKDLGIADNDWIEVFNSNGALTARAVVSQRVPAGMTMM
YHAQERIVNLPGSEITQQRGGIHNSVTRITPKPTHMIGGYAHLAYGFNYY
GTVGSNRDEFVVVRKMKNIDWLDGEGNDQVQES

3D structure

• PDB: 3ir6 Protein crystallography reveals a role for the FS0 cluster of Escherichia coli nitrate reductase A (NarGHI) in enzyme maturation.
• Chain: A
• Resolution: 2.8 Å

Enzymatic activity

• Catalytic site (original residue number in PDB): R94 P190 W219 Y220 P224
• Catalytic site (residue number reindexed from 1): R84 P180 W209 Y210 P214
• Enzyme Commision number: 1.7.5.1: nitrate reductase (quinone).

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	GDP	A	Y220 R713 S714 N715 S719 S720 L771 D772 F773 R774 T788 W791 K794 D822 H1098 S1099 T1100	Y210 R702 S703 N704 S708 S709 L760 D761 F762 R763 T777 W780 K783 D811 H1087 S1088 T1089
BS02	GDP	A	G253 N255 T259 V280 T281 P282 D283 D302 G541 A542 G543 L544 W547 P1091 H1092	G243 N245 T249 V270 T271 P272 D273 D292 G531 A532 G533 L534 W537 P1080 H1081

Gene Ontology

Molecular Function

• GO:0005515 protein binding
• GO:0008940 nitrate reductase activity
• GO:0009055 electron transfer activity
• GO:0016491 oxidoreductase activity
• GO:0043546 molybdopterin cofactor binding
• GO:0046872 metal ion binding
• GO:0051539 4 iron, 4 sulfur cluster binding
• GO:0160182 nitrate reductase (quinone) activity

Biological Process

• GO:0009061 anaerobic respiration
• GO:0019645 anaerobic electron transport chain
• GO:0042126 nitrate metabolic process
• GO:0042128 nitrate assimilation
• GO:0045333 cellular respiration

Cellular Component

• GO:0005886 plasma membrane
• GO:0009325 nitrate reductase complex
• GO:0016020 membrane
• GO:0044799 NarGHI complex
• GO:1990204 oxidoreductase complex

External links

• PDB: RCSB:3ir6, PDBe:3ir6, PDBj:3ir6
• PDBsum: 3ir6
• PubMed: 20053990
• UniProt: P09152|NARG_ECOLI Respiratory nitrate reductase 1 alpha chain (Gene Name=narG)