E7FI44 · HYD1A_PYRFU

Function

function

Part of a bifunctional enzyme complex that functions as an NADPH-dependent hydrogen-evolving hydrogenase with sulfur-reducing activity. May play a role in hydrogen cycling during fermentative growth. Activity not exhibited with NAD. The alpha and delta subunits form the hydrogenase component that catalyzes the reduction of protons to evolve hydrogen.

Catalytic activity

Cofactor

Protein has several cofactor binding sites:
Ni2+ (UniProtKB | Rhea| CHEBI:49786 )

Note: Binds 1 nickel ion per heterotetramer.
Fe cation (UniProtKB | Rhea| CHEBI:24875 )

Kinetics

KM SUBSTRATE pH TEMPERATURE[C] NOTES EVIDENCE
5.3 mMmethyl viologen
79 μMferredoxin
0.08 mMmethylene blue
70 μMferredoxin (sodium dithionate as cosubstrate)
1 μMferredoxin (pyruvate and NADP as cosubstrates)
40 μMNADP (pure H2 as cosubstrate)
0.2 mMNADPH (H+ as cosubstrate)
3 mMNADH (H+ as cosubstrate)
5 mMmethyl viologen (H2 as cosubstrate)
Vmax pH TEMPERATURE[C] NOTES EVIDENCE
2900 μmol/min/mgwith methyl viologen as substrate
18 μmol/min/mgwith ferredoxin as substrate (pyruvate and NADP as cosubstrates)
250 μmol/min/mgwith ferredoxin as substrate
261 μmol/min/mgwith methylene blue as substrate
67 μmol/min/mgwith ferredoxin as substrate (sodium dithionate as cosubstrate)
75 μmol/min/mgwith NADP as substrate (pure H2 as cosubstrate)
10 μmol/min/mgwith NADPH as substrate (H+ as cosubstrate)
6 μmol/min/mgwith NADPH as substrate (H+ as electron acceptor)
1.6 μmol/min/mgwith NADH as substrate (H+ as cosubstrate)
250 μmol/min/mgwith methyl viologen as substrate (H2 as cosubstrate)
Measured for the whole complex.

pH Dependence

Optimum pH is 8 for hydrogenase activity at >95 degrees Celsius.

Temperature Dependence

Optimum temperature is greater than 95 degrees Celsius for hydrogenase activity. Stable up to 100 degrees Celsius. Loses 50% of activity at 80 degrees Celsius after 21 hour incubation.

Features

Showing features for binding site.

TypeIDPosition(s)Description
Binding site65Ni2+ (UniProtKB | ChEBI)
Binding site68Fe cation (UniProtKB | ChEBI)
Binding site68Ni2+ (UniProtKB | ChEBI)
Binding site418Ni2+ (UniProtKB | ChEBI)
Binding site421Fe cation (UniProtKB | ChEBI)
Binding site421Ni2+ (UniProtKB | ChEBI)

GO annotations

AspectTerm
Cellular Component[Ni-Fe] hydrogenase complex
Cellular Componentcytoplasm
Molecular Functionferredoxin hydrogenase activity
Molecular Functionhydrogen dehydrogenase (NADP+) activity
Molecular Functionnickel cation binding

Keywords

Enzyme and pathway databases

Names & Taxonomy

Protein names

  • Recommended name
    Sulfhydrogenase 1 subunit alpha
  • EC number
  • Alternative names
    • Hydrogenase I large subunit
    • NADP-reducing hydrogenase subunit HydA
    • Sulfhydrogenase I subunit alpha

Gene names

    • Name
      hydA
    • Ordered locus names
      PF0894

Organism names

Accessions

  • Primary accession
    E7FI44
  • Secondary accessions
    • Q59670
    • Q7LWZ8

Proteomes

Subcellular Location

Keywords

PTM/Processing

Features

Showing features for chain.

TypeIDPosition(s)Description
ChainPRO_00004207221-428Sulfhydrogenase 1 subunit alpha

Proteomic databases

Interaction

Subunit

Heterotetramer of alpha, beta, gamma and delta subunits. The nickel-containing alpha and delta subunits constitute the hydrogenase activity. The beta and gamma subunits (flavin-containing dimer) constitute the sulfur reductase activity.

Protein-protein interaction databases

Structure

Family & Domains

Sequence similarities

Belongs to the [NiFe]/[NiFeSe] hydrogenase large subunit family.

Phylogenomic databases

Family and domain databases

Sequence

  • Sequence status
    Complete
  • Length
    428
  • Mass (Da)
    48,316
  • Last updated
    2011-03-08 v1
  • Checksum
    73856DFC716B5DCE
MKNLYLPITIDHIARVEGKGGVEIIIGDDGVKEVKLNIIEGPRFFEAITIGKKLEEALAIYPRICSFCSAAHKLTALEAAEKAVGFVPREEIQALREVLYIGDMIESHALHLYLLVLPDYRGYSSPLKMVNEYKREIEIALKLKNLGTWMMDILGSRAIHQENAVLGGFGKLPEKSVLEKMKAELREALPLAEYTFELFAKLEQYSEVEGPITHLAVKPRGDAYGIYGDYIKASDGEEFPSEKYRDYIKEFVVEHSFAKHSHYKGRPFMVGAISRVINNADLLYGKAKELYEANKDLLKGTNPFANNLAQALEIVYFIERAIDLLDEALAKWPIKPRDEVEIKDGFGVSTTEAPRGILVYALKVENGRVSYADIITPTAFNLAMMEEHVRMMAEKHYNDDPERLKILAEMVVRAYDPCISCSVHVVRL

Keywords

Sequence databases

Nucleotide SequenceProtein SequenceMolecule TypeStatus
X75255
EMBL· GenBank· DDBJ
CAA53037.1
EMBL· GenBank· DDBJ
Genomic DNA
AE009950
EMBL· GenBank· DDBJ
AAL81018.1
EMBL· GenBank· DDBJ
Genomic DNA

Genome annotation databases

Similar Proteins

Disclaimer

Any medical or genetic information present in this entry is provided for research, educational and informational purposes only. It is not in any way intended to be used as a substitute for professional medical advice, diagnosis, treatment or care. Our staff consists of biologists and biochemists that are not trained to give medical advice.
We'd like to inform you that we have updated our Privacy Notice to comply with Europe’s new General Data Protection Regulation (GDPR) that applies since 25 May 2018.
FeedbackHelp