Q9FEP8 · LGB3_LOTJA

Function

function

Leghemoglobin that reversibly binds oxygen O2 through a pentacoordinated heme iron (By similarity).
In root nodules, facilitates the diffusion of oxygen to the bacteroids while preventing the bacterial nitrogenase from being inactivated by buffering dioxygen, nitric oxide and carbon monoxide, and promoting the formation of reactive oxygen species (ROS, e.g. H2O2) (PubMed:15797021, PubMed:17540516, PubMed:17990967, PubMed:19522562, PubMed:31355948, PubMed:32442331).
This role is essential for symbiotic nitrogen fixation (SNF) (PubMed:15797021, PubMed:17540516, PubMed:17990967, PubMed:19522562, PubMed:31355948, PubMed:32442331).

Features

Showing features for binding site.

114720406080100120140
TypeIDPosition(s)Description
Binding site45heme b (UniProtKB | ChEBI)
Binding site61O2 (UniProtKB | ChEBI)
Binding site64heme b (UniProtKB | ChEBI)
Binding site93Fe (UniProtKB | ChEBI) of heme b (UniProtKB | ChEBI); proximal binding residue
Binding site96heme b (UniProtKB | ChEBI)

GO annotations

all annotationsall molecular functionnucleotide bindingmolecular_functionnucleic acid bindingdna bindingchromatin bindingdna-binding transcription factor activityrna bindingcytoskeletal motor activitycatalytic activitynuclease activitysignaling receptor bindingstructural molecule activitytransporter activitybindingprotein bindingtranslation factor activity, rna bindinglipid bindingkinase activitytransferase activityhydrolase activityoxygen bindingenzyme regulator activitycarbohydrate bindingsignaling receptor activitytranslation regulator activitytranscription regulator activityother molecular functionall biological processcarbohydrate metabolic processgeneration of precursor metabolites and energynucleobase-containing compound metabolic processdna metabolic processtranslationlipid metabolic processtransportresponse to stresscell cyclecell communicationsignal transductioncell-cell signalingmulticellular organism developmentcircadian rhythmbiological_processmetabolic processcatabolic processbiosynthetic processresponse to light stimulusresponse to external stimulustropismresponse to biotic stimulusresponse to abiotic stimulusresponse to endogenous stimulusembryo developmentpost-embryonic developmentfruit ripeningabscissionpollinationflower developmentcellular processprogrammed cell deathphotosynthesiscellular component organizationcell growthprotein metabolic processcellular homeostasissecondary metabolic processreproductive processcell differentiationprotein modification processgrowthepigenetic regulation of gene expressionresponse to chemicalanatomical structure developmentregulation of molecular functionother biological processall cellular componentcellular_componentextracellular regioncell wallintracellular anatomical structurenucleusnuclear envelopenucleoplasmnucleoluscytoplasmmitochondrionlysosomeendosomevacuoleperoxisomeendoplasmic reticulumgolgi apparatuscytosolribosomecytoskeletonplasma membranechloroplastplastidthylakoidmembraneexternal encapsulating structureother cellular component
Cell color indicative of number of GO terms
AspectTerm
Cellular Componentcytosol
Cellular Componenthost bacteroid-containing symbiosome
Cellular Componentnucleus
Molecular Functionheme binding
Molecular Functionmetal ion binding
Molecular Functionoxygen binding
Molecular Functionoxygen carrier activity
Biological Processintracellular oxygen homeostasis
Biological Processnitrogen fixation
Biological Processnodulation
Biological Processresponse to symbiotic bacterium

Keywords

Names & Taxonomy

Protein names

  • Recommended name
    Leghemoglobin 3
  • Short names
    LjLb3
  • Alternative names
    • Symbiotic hemoglobin Lb3
      (Sym-Hb Lb3
      )

Gene names

    • Name
      LB3
    • ORF names
      Lj5g3v0465970
      , LotjaGi5g1v0046500

Organism names

  • Taxonomic identifier
  • Strains
    • cv. Gifu
    • cv. MG-20
  • Taxonomic lineage
    Eukaryota > Viridiplantae > Streptophyta > Embryophyta > Tracheophyta > Spermatophyta > Magnoliopsida > eudicotyledons > Gunneridae > Pentapetalae > rosids > fabids > Fabales > Fabaceae > Papilionoideae > 50 kb inversion clade > NPAAA clade > Hologalegina > robinioid clade > Loteae > Lotus

Accessions

  • Primary accession
    Q9FEP8
  • Secondary accessions
    • Q3C1F5

Subcellular Location

Keywords

Phenotypes & Variants

Disruption phenotype

Normal growth and flowering under non-restrictive nutrient conditions, but classic symptoms of extreme nitrogen limitation under restrictive nutrient conditions, including severely stunted growth, increased root/shoot ratio and delayed flowering (PubMed:15797021).
Following inoculation with symbiotic rhizobia, accumulation of free oxygen at the expense of reactive oxygen species (ROS, e.g. H2O2) production in root nodules leading to the loss of bacterial nitrogenase protein and the absence of symbiotic nitrogen fixation (SNF), as well as decreased ATP/ADP ratio; bacteroids of these impaired nodules exhibit altered ultrastructure due to disturbed bacterial differentiation (PubMed:15797021, PubMed:17990967).
In symbiotic conditions, plants lacking leghemoglobins lb13, lb23 and lb123 have reduced growth and exhibit lower N2 fixation in root nodules displaying ultrastructural alterations including abnormal mitochondria and large lytic vacuoles, associated with increased reactive oxygen species (ROS) accumulation as well as early nodules senescence (PubMed:31355948).

PTM/Processing

Features

Showing features for initiator methionine, chain, modified residue.

TypeIDPosition(s)Description
Initiator methionine1Removed
ChainPRO_00001929832-147Leghemoglobin 3
Modified residue30Nitrated tyrosine
Modified residue45Phosphoserine
Modified residue135Nitrated tyrosine

Post-translational modification

Nitrated in effective nodules and particularly in hypoxic conditions; this mechanism may play a protective role in the symbiosis by buffering toxic peroxynitrite NO2-. Nitration level decrease during nodule senescence.
Phosphorylation at Ser-45 disrupts the molecular environment of its porphyrin ring oxygen binding pocket, thus leading to a reduced oxygen consumption and to the delivery of oxygen O2 to symbiosomes.

Keywords

Expression

Tissue specificity

Specifically and strongly expressed in root nodules and at low levels in seedlings.

Induction

Accumulates in developing root nodules upon inoculation with the symbiotic M.loti strain MAFF303099.

Developmental stage

In nodulating roots, accumulates during nodule maturation, and fades out progressively in aging and senescent nodules.

Interaction

Subunit

Monomer.

Structure

Family & Domains

Features

Showing features for domain.

TypeIDPosition(s)Description
Domain2-147Globin

Sequence similarities

Belongs to the plant globin family.

Family and domain databases

Sequence

  • Sequence status
    Complete
  • Length
    147
  • Mass (Da)
    15,755
  • Last updated
    2001-03-01 v1
  • Checksum
    E62DE1BE4E523E77
MGFTAQQEALVGSSYETFKKNLPTNSVLFYTVILEIAPTAKDMFSFLKESGPKHSPQLQAHAEKVFALTRDAATQLVAKGEVTLADASLGAVHVQKAVTDPHFVVVKEALLQTVKEAVGADEWSDDLSTAWEGAYDGLATAIKKAMG

Sequence databases

Nucleotide SequenceProtein SequenceMolecule TypeStatus
AB042718
EMBL· GenBank· DDBJ
BAB18108.1
EMBL· GenBank· DDBJ
Genomic DNA
AB238219
EMBL· GenBank· DDBJ
BAE46738.1
EMBL· GenBank· DDBJ
mRNA
BT134204
EMBL· GenBank· DDBJ
AFK33999.1
EMBL· GenBank· DDBJ
mRNA
BT147367
EMBL· GenBank· DDBJ
AFK47161.1
EMBL· GenBank· DDBJ
mRNA

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