P26254 (NIFH_TRITH) Reviewed, UniProtKB/Swiss-Prot

Names and origin

Protein names

Recommended name:
Nitrogenase iron protein
EC=1.18.6.1

Alternative name(s):
Nitrogenase Fe protein
Nitrogenase component II
Nitrogenase reductase

Gene names

Name:

nifH

Organism

Trichodesmium thiebautii

Taxonomic identifier

1208 [NCBI]

Taxonomic lineage

Bacteria › Cyanobacteria › Oscillatoriales › Trichodesmium

Protein attributes

Sequence length	294 AA.
Sequence status	Complete.
Protein existence	Inferred from homology

General annotation (Comments)

Function	The key enzymatic reactions in nitrogen fixation are catalyzed by the nitrogenase complex, which has 2 components: the iron protein and the molybdenum-iron protein. HAMAP MF_00533
Catalytic activity	8 reduced ferredoxin + 8 H+ + N2 + 16 ATP + 16 H2O = 8 oxidized ferredoxin + H2 + 2 NH3 + 16 ADP + 16 phosphate. HAMAP MF_00533
Cofactor	Binds 1 4Fe-4S cluster per dimer.
Subunit structure	Homodimer.
Post-translational modification	The reversible ADP-ribosylation of Arg-100 inactivates the nitrogenase reductase and regulates nitrogenase activity By similarity. HAMAP MF_00533
Sequence similarities	Belongs to the NifH/BchL/ChlL family.

Ontologies

Keywords
Biological process	Nitrogen fixation
Ligand	4Fe-4S ATP-binding Iron Iron-sulfur Metal-binding Nucleotide-binding
Molecular function	Oxidoreductase
PTM	ADP-ribosylation
Gene Ontology (GO)
Biological process	nitrogen fixation Inferred from electronic annotation. Source: UniProtKB-KW
Cellular component	molybdenum-iron nitrogenase complex Inferred from electronic annotation. Source: InterPro
Molecular function	4 iron, 4 sulfur cluster binding Inferred from electronic annotation. Source: UniProtKB-KW ATP binding Inferred from electronic annotation. Source: UniProtKB-KW carbonyl sulfide nitrogenase activity Inferred from electronic annotation. Source: EC metal ion binding Inferred from electronic annotation. Source: UniProtKB-KW nitrogenase activity Inferred from electronic annotation. Source: EC
Complete GO annotation...

Sequence annotation (Features)

	Feature key	Position(s)	Length	Description	Graphical view	Feature identifier
Molecule processing
	Chain	1 – 294	294	Nitrogenase iron protein HAMAP MF_00533		PRO_0000139534
Regions
	Nucleotide binding	8 – 15	8	ATP Potential
Sites
	Metal binding	97	1	Iron-sulfur (4Fe-4S); shared with dimeric partner By similarity
	Metal binding	131	1	Iron-sulfur (4Fe-4S); shared with dimeric partner By similarity
Amino acid modifications
	Modified residue	100	1	ADP-ribosylarginine; by dinitrogenase reductase ADP-ribosyltransferase By similarity
Experimental info
	Sequence conflict	50	1	D → N in AAA27368. Ref.2

Sequences

	Sequence		Length	Mass (Da)
	P26254 [UniParc]. Last modified January 23, 2002. Version 2. Checksum: E39256D868743608	FASTA	294	32,276
	10 20 30 40 50 60 MRQIAFYGKG GIGKSTTSQN TLAAMANRHG QRIMIVGCDP KADSTRLILD AKAQTTVLHV 70 80 90 100 110 120 AAELGAVEDV ELDQVLKPGF GGIKCVESGG PEPGVGCAGR GIITAINFLE EEGAYTDLDF 130 140 150 160 170 180 VSYDVLGDVV CGGFAMPIRE NKAQEIYIVC SGEMMAMYAA NNIARGVLKY AHAGGVRLGG 190 200 210 220 230 240 LICNSRKVDR ETELIENLAA RLNTQMIHFV PRDNVVQRAE IRRLTVEQYA PEDNQAQEYN 250 260 270 280 290 KLAEKIINNE KLTIPTPLEM DELEELLIEF GLLAATKKIV RNKLQHKMQQ QQKK

References

[1]	"Isolation of nifH and part of nifD by modified capture PCR from a natural population of the marine cyanobacterium Trichodesmium thiebautii." Sroga G.E., Landegren U., Bergman B., Lagerstrom-Fermer M. Submitted (MAR-1995) to the EMBL/GenBank/DDBJ databases Cited for: NUCLEOTIDE SEQUENCE [GENOMIC DNA].
[2]	"Use of degenerate oligonucleotides for amplification of the nifH gene from the marine cyanobacterium Trichodesmium thiebautii." Zehr J.P., McReynolds L.A. Appl. Environ. Microbiol. 55:2522-2526(1989) [PubMed: 2513774] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [GENOMIC DNA] OF 38-156.
+	Additional computationally mapped references.

Cross-references

Sequence databases
EMBL GenBank DDBJ	U23507 Genomic DNA. Translation: AAA77022.1. M29709 Genomic DNA. Translation: AAA27368.1.
PIR	A43635.
3D structure databases
ProteinModelPortal	P26254.
SMR	P26254. Positions 1-273.
ModBase	Search...
Protocols and materials databases
StructuralBiologyKnowledgebase	Search...
Family and domain databases
HAMAP	MF_00533. NifH. [Tree]
InterPro	IPR000392. Nitogenase_NifH/Reductase_ChlL. IPR005977. Nitrogenase_Fe_NifH. [Graphical view]
PANTHER	PTHR13696:SF32. PTHR13696:SF32. 1 hit.
Pfam	PF00142. Fer4_NifH. 1 hit. [Graphical view]
PIRSF	PIRSF000363. Nitrogenase_iron. 1 hit.
PRINTS	PR00091. NITROGNASEII.
TIGRFAMs	TIGR01287. NifH. 1 hit.
PROSITE	PS00746. NIFH_FRXC_1. 1 hit. PS00692. NIFH_FRXC_2. 1 hit. PS51026. NIFH_FRXC_3. 1 hit. [Graphical view]
ProtoNet	Search...

Entry information

Entry name

NIFH_TRITH

Accession

Primary (citable) accession number: P26254
Secondary accession number(s): Q56373

Entry history

Integrated into UniProtKB/Swiss-Prot:	May 1, 1992
Last sequence update:	January 23, 2002
Last modified:	October 19, 2011
This is version 78 of the entry and version 2 of the sequence. [Complete history]

Entry status

Reviewed (UniProtKB/Swiss-Prot)

Annotation program

Prokaryotic Protein Annotation Program