Structure of PDB 4tku Chain B

Receptor sequence

>4tkuB (length=522) Species: 354 (Azotobacter vinelandii)

SQQVDKIKASYPLFLDQDYKDMLAKKRDGFEEKYPQDKIDEVFQWTTTKE
YQELNFQREALTVNPAKACQPLGAVLCALGFEKTMPYVHGSQGCVAYFRS
YFNRHFREPVSCVSDSMTEDAAVFGGQQNMKDGLQNCKATYKPDMIAVST
TCMAEVIGDDLNAFINNSKKEGFIPDEFPVPFAHTPSFVGSHVTGWDNMF
EGIARYFTLKSMDDKVVGSNKKINIVPGFETYLGNFRVIKRMLSEMGVGY
SLLSDPEEVLDTPADGQFRMYAGGTTQEEMKDAPNALNTVLLQPWHLEKT
KKFVEGTWKHEVPKLNIPMGLDWTDEFLMKVSEISGQPIPASLTKERGRL
VDMMTDSHTWLHGKRFALWGDPDFVMGLVKFLLELGCEPVHILCHNGNKR
WKKAVDAILAASPYGKNATVYIGKDLWHLRSLVFTDKPDFMIGNSYGKFI
QRDTLHKGKEFEVPLIRIGFPIFDRHHLHRSTTLGYEGAMQILTTLVNSI
LERLDEETRGMQATDYNHDLVR

3D structure

• PDB: 4tku Ligand binding to the FeMo-cofactor: structures of CO-bound and reactivated nitrogenase.
• Chain: B
• Resolution: 1.43 Å

Enzymatic activity

• Catalytic site (original residue number in PDB): C153 V157
• Catalytic site (residue number reindexed from 1): C152 V156
• Enzyme Commision number: 1.18.6.1: nitrogenase.

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	CLF	B	C70 G94 C95 Y98 T152 C153 S188	C69 G93 C94 Y97 T151 C152 S187
BS02	FE2	B	D353 D357	D352 D356
BS03	FE2	B	R108 E109	R107 E108

Gene Ontology

Molecular Function

• GO:0005524 ATP binding
• GO:0016163 nitrogenase activity
• GO:0016491 oxidoreductase activity
• GO:0046872 metal ion binding
• GO:0051536 iron-sulfur cluster binding

Biological Process

• GO:0009399 nitrogen fixation

Cellular Component

• GO:0016612 molybdenum-iron nitrogenase complex

External links

• PDB: RCSB:4tku, PDBe:4tku, PDBj:4tku
• PDBsum: 4tku
• PubMed: 25258081
• UniProt: P07329|NIFK_AZOVI Nitrogenase molybdenum-iron protein beta chain (Gene Name=nifK)