P38755 · OSH7_YEAST
- ProteinOxysterol-binding protein homolog 7
- GeneOSH7
- StatusUniProtKB reviewed (Swiss-Prot)
- Amino acids437 (go to sequence)
- Protein existenceEvidence at protein level
- Annotation score5/5
Function
function
ipid transport protein (LTP) involved in non-vesicular transfer of lipids between membranes. Functions in phosphoinositide-coupled directional transport of various lipids by carrying the lipid molecule in a hydrophobic pocket and transferring it between membranes through the cytosol. Involved in maintenance of intracellular sterol distribution and homeostasis (PubMed:15173322).
Involved in lipid countertransport between the endoplasmic reticulum and the plasma membrane. Specifically exchanges phosphatidylserine with phosphatidylinositol 4-phosphate (PI4P), delivering phosphatidylserine to the PM in exchange for PI4P, which is delivered to the ER-localized PI4P phosphatase SAC1 for degradation. Thus, by maintaining a PI4P gradient at the ER/PM interface, SAC1 drives PS transport (PubMed:23934110, PubMed:26206936).
Binds phosphatidylserine and PI4P in a mutually exclusive manner (PubMed:26206936).
Involved in lipid countertransport between the endoplasmic reticulum and the plasma membrane. Specifically exchanges phosphatidylserine with phosphatidylinositol 4-phosphate (PI4P), delivering phosphatidylserine to the PM in exchange for PI4P, which is delivered to the ER-localized PI4P phosphatase SAC1 for degradation. Thus, by maintaining a PI4P gradient at the ER/PM interface, SAC1 drives PS transport (PubMed:23934110, PubMed:26206936).
Binds phosphatidylserine and PI4P in a mutually exclusive manner (PubMed:26206936).
Miscellaneous
Present with 2350 molecules/cell in log phase SD medium.
Catalytic activity
- a 1,2-diacyl-sn-glycero-3-phospho-L-serine(in) = a 1,2-diacyl-sn-glycero-3-phospho-L-serine(out)This reaction proceeds in the forward direction.
Features
Showing features for binding site.
Type | ID | Position(s) | Description | ||
---|---|---|---|---|---|
Binding site | 64-69 | a 1,2-diacyl-sn-glycero-3-phospho-(1D-myo-inositol 4-phosphate) (UniProtKB | ChEBI) | |||
Binding site | 64-69 | a 1,2-diacyl-sn-glycero-3-phospho-L-serine (UniProtKB | ChEBI) | |||
Binding site | 126-129 | a 1,2-diacyl-sn-glycero-3-phospho-(1D-myo-inositol 4-phosphate) (UniProtKB | ChEBI) | |||
Binding site | 129 | a 1,2-diacyl-sn-glycero-3-phospho-L-serine (UniProtKB | ChEBI) | |||
Binding site | 157-158 | a 1,2-diacyl-sn-glycero-3-phospho-(1D-myo-inositol 4-phosphate) (UniProtKB | ChEBI) | |||
Binding site | 183 | a 1,2-diacyl-sn-glycero-3-phospho-L-serine (UniProtKB | ChEBI) | |||
Binding site | 351 | a 1,2-diacyl-sn-glycero-3-phospho-(1D-myo-inositol 4-phosphate) (UniProtKB | ChEBI) | |||
Binding site | 355 | a 1,2-diacyl-sn-glycero-3-phospho-(1D-myo-inositol 4-phosphate) (UniProtKB | ChEBI) | |||
Binding site | 359 | a 1,2-diacyl-sn-glycero-3-phospho-(1D-myo-inositol 4-phosphate) (UniProtKB | ChEBI) | |||
GO annotations
Aspect | Term | |
---|---|---|
Cellular Component | cortical endoplasmic reticulum | |
Cellular Component | cytoplasm | |
Cellular Component | cytosol | |
Cellular Component | endoplasmic reticulum membrane | |
Cellular Component | membrane | |
Cellular Component | plasma membrane | |
Molecular Function | lipid binding | |
Molecular Function | phosphatidylinositol-4-phosphate binding | |
Molecular Function | phosphatidylserine binding | |
Molecular Function | phospholipid transporter activity | |
Molecular Function | sterol binding | |
Molecular Function | sterol transfer activity | |
Biological Process | endocytosis | |
Biological Process | exocytosis | |
Biological Process | late endosome to vacuole transport | |
Biological Process | maintenance of cell polarity | |
Biological Process | phospholipid transport | |
Biological Process | piecemeal microautophagy of the nucleus | |
Biological Process | sterol metabolic process | |
Biological Process | sterol transport |
Keywords
- Biological process
- Ligand
Enzyme and pathway databases
Protein family/group databases
Names & Taxonomy
Protein names
- Recommended nameOxysterol-binding protein homolog 7
- Alternative names
Gene names
Organism names
- Strain
- Taxonomic lineageEukaryota > Fungi > Dikarya > Ascomycota > Saccharomycotina > Saccharomycetes > Saccharomycetales > Saccharomycetaceae > Saccharomyces
Accessions
- Primary accessionP38755
- Secondary accessions
Proteomes
Organism-specific databases
Subcellular Location
UniProt Annotation
GO Annotation
Note: Localizes to the cortical endoplasmic reticulum at the endoplasmic reticulum-plasma membrane contact sites.
Keywords
- Cellular component
PTM/Processing
Features
Showing features for chain, cross-link.
Type | ID | Position(s) | Description | ||
---|---|---|---|---|---|
Chain | PRO_0000100391 | 1-437 | Oxysterol-binding protein homolog 7 | ||
Cross-link | 276 | Glycyl lysine isopeptide (Lys-Gly) (interchain with G-Cter in ubiquitin) | |||
Keywords
- PTM
Proteomic databases
PTM databases
Structure
Family & Domains
Features
Showing features for region.
Type | ID | Position(s) | Description | ||
---|---|---|---|---|---|
Region | 23-42 | Disordered | |||
Region | 54-393 | OSBP-related domain (ORD) | |||
Domain
The OSBP-related domain (ORD) mediates binding of sterols and phospholipids. It displays an incomplete beta-barrel containing a central hydrophobic tunnel that can accommodate a single lipid molecule with a flexible lid covering the tunnel entrance. The ORD can bind two membranes simultaneously. It has at least two membrane-binding surfaces; one near the mouth of the lipid-binding pocket and a distal site that can bind a second membrane. These structural features correlate with the phosphatidylinositol 4-phosphate (PI4P)-coupled lipid transport optimized in closely apposed membranes, such as organelle contact sites. The lipid transfer cycle starts from the association of the LTP with a donor membrane, which accompanies conformational changes that uncover the ligand-binding pocket. The tunnel opening is generally mediated by displacement of the lid covering the binding pocket allowing uptake or release of a lipid molecule. The LTPs extract the lipid from the membrane by providing a hydrophobic environment as well as specific interaction. Dissociation from the donor membrane shifts the conformation to a closed form. Then, the LTPs loaded with a cargo lipid diffuse through the aqueous phase. Lid opening may be induced by the interaction of a hydrophobic side of the lid with the target membranes.
Sequence similarities
Belongs to the OSBP family.
Phylogenomic databases
Family and domain databases
Sequence
- Sequence statusComplete
- Length437
- Mass (Da)49,805
- Last updated1995-02-01 v1
- Checksum1C972ED6517D529B
Keywords
- Technical term
Sequence databases
Nucleotide Sequence | Protein Sequence | Molecule Type | Status | |
---|---|---|---|---|
U10555 EMBL· GenBank· DDBJ | AAB68425.1 EMBL· GenBank· DDBJ | Genomic DNA | ||
AY692903 EMBL· GenBank· DDBJ | AAT92922.1 EMBL· GenBank· DDBJ | Genomic DNA | ||
BK006934 EMBL· GenBank· DDBJ | DAA06687.1 EMBL· GenBank· DDBJ | Genomic DNA |