ID:OSTB_HUMAN DESCRIPTION: RecName: Full=Organic solute transporter subunit beta; Short=OST-beta; AltName: Full=Solute carrier family 51 subunit beta; FUNCTION: Essential component of the Ost-alpha/Ost-beta complex, a heterodimer that acts as the intestinal basolateral transporter responsible for bile acid export from enterocytes into portal blood. Efficiently transports the major species of bile acids. Modulates SLC51A glycosylation, membrane trafficking and stability activities. SUBUNIT: Interacts with SLC51A. The Ost-alpha/Ost-beta complex is a heterodimer composed of alpha (SLC51A) and beta (SLC51B) subunit; induces the transport of SLC51A from the reticulum endoplasmic to the plasma membrane (By similarity). SUBCELLULAR LOCATION: Cell membrane; Single-pass membrane protein. Note=Mainly restricted to the lateral and basal membranes of ileal enterocytes. TISSUE SPECIFICITY: Widely expressed with a high expression in ileum. Expressed in testis, colon, liver, small intestine, kidney, ovary and adrenal gland; and at low levels in heart, lung, brain, pituitary, thyroid gland, uterus, prostate, mammary gland and fat. INDUCTION: Positively regulated via NR1H4/FXR. DOMAIN: The transmembrane domain (TM) is the major site of interaction with SLC51A. The extracellular-membrane interface is absolutely required for transport activity. The intracellular- membrane interface is necessary for establishing the correct membrane orientation that is essential for the heterodimer Ost- alpha/Ost-beta complex formation and transport activity at the cell membrane surface (By similarity). SIMILARITY: Belongs to the OST-beta family.
The RNAfold program from the Vienna RNA Package is used to perform the secondary structure predictions and folding calculations. The estimated folding energy is in kcal/mol. The more negative the energy, the more secondary structure the RNA is likely to have.
Protein Domain and Structure Information
Pfam Domains: PF15048 - Organic solute transporter subunit beta protein
ModBase Predicted Comparative 3D Structure on Q86UW2
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Orthologous Genes in Other Species
Orthologies between human, mouse, and rat are computed by taking the best BLASTP hit, and filtering out non-syntenic hits. For more distant species reciprocal-best BLASTP hits are used. Note that the absence of an ortholog in the table below may reflect incomplete annotations in the other species rather than a true absence of the orthologous gene.
Gene Ontology (GO) Annotations with Structured Vocabulary
Molecular Function: GO:0005215 transporter activity GO:0015125 bile acid transmembrane transporter activity GO:0022857 transmembrane transporter activity GO:0046982 protein heterodimerization activity
Biological Process: GO:0015721 bile acid and bile salt transport GO:0031647 regulation of protein stability GO:0032782 bile acid secretion GO:0055085 transmembrane transport GO:0060050 positive regulation of protein glycosylation GO:0070863 positive regulation of protein exit from endoplasmic reticulum GO:0071702 organic substance transport GO:0090314 positive regulation of protein targeting to membrane
US Server
Sequence and Links to Tools and Databases 
Common Gene Haplotype Alleles 
