Q9FEP8 · LGB3_LOTJA
- ProteinLeghemoglobin 3
- GeneLB3
- StatusUniProtKB reviewed (Swiss-Prot)
- Amino acids147 (go to sequence)
- Protein existenceEvidence at transcript level
- Annotation score5/5
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).
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.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Binding site | 45 | heme b (UniProtKB | ChEBI) | ||||
Sequence: S | ||||||
Binding site | 61 | O2 (UniProtKB | ChEBI) | ||||
Sequence: H | ||||||
Binding site | 64 | heme b (UniProtKB | ChEBI) | ||||
Sequence: K | ||||||
Binding site | 93 | Fe (UniProtKB | ChEBI) of heme b (UniProtKB | ChEBI); proximal binding residue | ||||
Sequence: H | ||||||
Binding site | 96 | heme b (UniProtKB | ChEBI) | ||||
Sequence: K |
GO annotations
all annotations | all molecular function | nucleotide binding | molecular_function | nucleic acid binding | dna binding | chromatin binding | dna-binding transcription factor activity | rna binding | cytoskeletal motor activity | catalytic activity | nuclease activity | signaling receptor binding | structural molecule activity | transporter activity | binding | protein binding | translation factor activity, rna binding | lipid binding | kinase activity | transferase activity | hydrolase activity | oxygen binding | enzyme regulator activity | carbohydrate binding | signaling receptor activity | translation regulator activity | transcription regulator activity | other molecular function | all biological process | carbohydrate metabolic process | generation of precursor metabolites and energy | nucleobase-containing compound metabolic process | dna metabolic process | translation | lipid metabolic process | transport | response to stress | cell cycle | cell communication | signal transduction | cell-cell signaling | multicellular organism development | circadian rhythm | biological_process | metabolic process | catabolic process | biosynthetic process | response to light stimulus | response to external stimulus | tropism | response to biotic stimulus | response to abiotic stimulus | response to endogenous stimulus | embryo development | post-embryonic development | fruit ripening | abscission | pollination | flower development | cellular process | programmed cell death | photosynthesis | cellular component organization | cell growth | protein metabolic process | cellular homeostasis | secondary metabolic process | reproductive process | cell differentiation | protein modification process | growth | epigenetic regulation of gene expression | response to chemical | anatomical structure development | regulation of molecular function | other biological process | all cellular component | cellular_component | extracellular region | cell wall | intracellular anatomical structure | nucleus | nuclear envelope | nucleoplasm | nucleolus | cytoplasm | mitochondrion | lysosome | endosome | vacuole | peroxisome | endoplasmic reticulum | golgi apparatus | cytosol | ribosome | cytoskeleton | plasma membrane | chloroplast | plastid | thylakoid | membrane | external encapsulating structure | other cellular component | |||
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Aspect | Term | |
---|---|---|
Cellular Component | cytosol | |
Cellular Component | host bacteroid-containing symbiosome | |
Cellular Component | nucleus | |
Molecular Function | heme binding | |
Molecular Function | metal ion binding | |
Molecular Function | oxygen binding | |
Molecular Function | oxygen carrier activity | |
Biological Process | intracellular oxygen homeostasis | |
Biological Process | nitrogen fixation | |
Biological Process | nodulation | |
Biological Process | response to symbiotic bacterium |
Keywords
- Biological process
- Ligand
Names & Taxonomy
Protein names
- Recommended nameLeghemoglobin 3
- Short namesLjLb3
- Alternative names
Gene names
Organism names
- Strains
- Taxonomic lineageEukaryota > 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 accessionQ9FEP8
- Secondary accessions
Subcellular Location
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).
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.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Initiator methionine | 1 | Removed | ||||
Sequence: M | ||||||
Chain | PRO_0000192983 | 2-147 | Leghemoglobin 3 | |||
Sequence: GFTAQQEALVGSSYETFKKNLPTNSVLFYTVILEIAPTAKDMFSFLKESGPKHSPQLQAHAEKVFALTRDAATQLVAKGEVTLADASLGAVHVQKAVTDPHFVVVKEALLQTVKEAVGADEWSDDLSTAWEGAYDGLATAIKKAMG | ||||||
Modified residue | 30 | Nitrated tyrosine | ||||
Sequence: Y | ||||||
Modified residue | 45 | Phosphoserine | ||||
Sequence: S | ||||||
Modified residue | 135 | Nitrated tyrosine | ||||
Sequence: Y |
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
- PTM
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.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Domain | 2-147 | Globin | ||||
Sequence: GFTAQQEALVGSSYETFKKNLPTNSVLFYTVILEIAPTAKDMFSFLKESGPKHSPQLQAHAEKVFALTRDAATQLVAKGEVTLADASLGAVHVQKAVTDPHFVVVKEALLQTVKEAVGADEWSDDLSTAWEGAYDGLATAIKKAMG |
Sequence similarities
Belongs to the plant globin family.
Family and domain databases
Sequence
- Sequence statusComplete
- Length147
- Mass (Da)15,755
- Last updated2001-03-01 v1
- ChecksumE62DE1BE4E523E77
Sequence databases
Nucleotide Sequence | Protein Sequence | Molecule Type | Status | |
---|---|---|---|---|
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 |