Structure of PDB 1aof Chain B

Receptor sequence

>1aofB (length=542) Species: 82367 (Paracoccus pantotrophus)

EPSLDNLAQQDVAAPGAPEGVTALSDAQYNEANKIYFERCAGCHGVLRKG
ATGKALTPDLTRDLGFDYLQSFITYASPAGMPNWGTSGELSAEQVDLMAN
YLLLDPAAPPEFGMKEMRESWKVHVAPEDRPTQQMNDWDLENLFSVTLRD
AGQIALIDGSTYEIKTVLDTGYAVHISRLSASGRYLFVIGRDGKVNMIDL
WMKEPTTVAEIKIGSEARSIETSKMEGWEDKYAIAGAYWPPQYVIMDGET
LEPKKIQSTRGMTYDEQEYHPEPRVAAILASHYRPEFIVNVKETGKILLV
DYTDLNNLKTTEISAERFLHDGGLDGSHRYFITAANARNKLVVIDTKEGK
LVAIEDTGGQTPHPGRGANFVHPTFGPVWATSHMGDDSVALIGTDPEGHP
DNAWKILDSFPALGGGSLFIKTHPNSQYLYVDATLNPEAEISGSVAVFDI
KAMTGDGSDPEFKTLPIAEWAGITEGQPRVVQGEFNKDGTEVWFSVWNGK
DQESALVVVDDKTLELKHVIKDERLVTPTGKFNVYNTMTDTY

3D structure

• PDB: 1aof Haem-ligand switching during catalysis in crystals of a nitrogen-cycle enzyme.
• Chain: B
• Resolution: 2.0 Å

Enzymatic activity

• Catalytic site (original residue number in PDB): C65 C68 H69 M106 H345 H388
• Catalytic site (residue number reindexed from 1): C40 C43 H44 M81 H320 H363
• Enzyme Commision number: 1.7.2.1: nitrite reductase (NO-forming).
  1.7.99.1: hydroxylamine reductase.

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	HEM	B	C65 C68 H69 G78 K79 L81 Y93 S102 A104 M106 P107 W109	C40 C43 H44 G53 K54 L56 Y68 S77 A79 M81 P82 W84
BS02	DHE	B	P27 R174 H200 I201 R216 R243 S244 Y263 A301 A302 H345 R391 F444 T554 F557	P2 R149 H175 I176 R191 R218 S219 Y238 A276 A277 H320 R366 F419 T529 F532

Gene Ontology

Molecular Function

• GO:0009055 electron transfer activity
• GO:0016491 oxidoreductase activity
• GO:0020037 heme binding
• GO:0046872 metal ion binding
• GO:0050418 hydroxylamine reductase activity
• GO:0050421 nitrite reductase (NO-forming) activity

Cellular Component

• GO:0042597 periplasmic space

External links

• PDB: RCSB:1aof, PDBe:1aof, PDBj:1aof
• PDBsum: 1aof
• PubMed: 9311786
• UniProt: P72181|NIRS_PARPN Nitrite reductase (Gene Name=nirS)