GTP-binding protein SAR1b; GTP-binding protein B; GTBPB (SAR1B, SARA2, SARB)

Function: - role in transport from the endoplasmic reticulum to the Golgi - activated by the guanine nucleotide exchange factor PREB - involved in the selection of the protein cargo & the assembly of the COP2 coat complex - binds PREB - part of the COP2 coat complex - binds to the cytoplasmic tails of target proteins in the endoplasmic reticulum (putative) Structure: - homodimer - belongs to the small GTPase superfamily, SAR1 family Compartment: - endoplasmic reticulum membrane - peripheral membrane protein (putative) - Golgi, Golgi stack membrane - associated with the endoplasmic reticulum & Golgi stacks, in particular in the juxta-nuclear Golgi region (putative) Expression: - expressed in many tissues including small intestine, liver, muscle & brain Pathology: - defects in SAR1B are the cause of chylomicron retention disease

General

guanosine triphosphatase (GTPase) guanine nucleotide regulatory protein (GNRP) prenyl protein

Properties

SIZE: entity length = 198 aa MW = 22 kD COMPARTMENT: cell nucleus golgi endoplasmic reticulum MOTIF: GTP-binding site SITE: 32-39 MOTIF: Mg+2-binding site SITE: 34-34 GTP-binding site SITE: 75-78 MOTIF: Mg+2-binding site SITE: 75-75 GTP-binding site SITE: 134-137

Database Correlations

OMIM correlations MORBIDMAP 607690 UniProt Q9Y6B6 Pfam PF00025 Entrez Gene 51128 Kegg hsa:51128

References

UniProt :accession Q9Y6B6