DDOST / OST48 Protein & Antibody

Dolichyl-diphosphooligosaccharide-protein glycosyltransferase / Oligosaccharyl transferase 48 kDa subunit

DDOST / OST48 Products

DDOST / OST48 Protein, Recombinant

Molecule	Species	Description	Cat. No
DDOST/OST48	Human	DDOST/OST48 Protein, Recombinant	12463-HNCE

DDOST / OST48 Antibody

Molecule	Application	Description	Cat. No
Human DDOST/OST48	WB, ELISA	DDOST / OST48 Antibody (Antigen Affinity Purified)	12463-RP02

DDOST / OST48 Related Areas

Enzyme>>Carbohydrate Metabolism Enzymes>>DDOST/OST48

DDOST / OST48 Alternative Names

DDOST, OST48, OK/SW-cl.45, AGER1, KIAA0115, MGC2191, OKSWcl45, OST, OST48, WBP1 [Homo sapiens]

Ddost, OST48, RP23-25C1.4 [Mus musculus]

DDOST / OST48 Background

The enzyme oligosaccharyltransferase (dolichyl-diphosphooligosaccharide-protein glycosyltransferase) (DDOST), or 48-kDa subunit (OST48) is one of the catalytic subunits in this complex, exerts a typical type I membrane topology, containing a large luminal domain, a hydrophobic transmembrane domain and a short cytosolic peptide tail. DDOST/OST48 catalyzes the transfer of a high-mannose oligosaccharide (GlcNac2Man9Glc3) from a dolichol-linked oligosaccharide donor (dolichol-P-GlcNac2Man9Glc3) onto the asparagine acceptor site within an Asn-X-Ser/Thr consensus motif in nascent polypeptide chains across the membrane of the endoplasmic reticulum. The mammalian oligosaccharyltransferase (OST) is an oligomeric complex composed of three type I transmembrane proteins of the endoplasmic reticulum: ribophorin I (RI), ribophorin II (RII), and OST48. OST48 is not a glycoprotein and is not recognized by antibodies to either ribophorin. Like ribophorins I and II, OST48 was found to be an integral membrane protein, with the majority of the polypeptide located within the lumen of the endoplasmic reticulum (ER). OST48 does not show significant amino acid sequence homology to either ribophorin I or II. It had been found that only the luminal domain of RI contains ER retention information. The dilysine motif in OST48 functions as an ER localization motif because OST48 in which the two lysine residues are replaced by serine (OST48ss) is no longer retained in the ER and is found instead also at the plasma membrane.

DDOST / OST48 Related Studies

1. Silberstein S, et al. (1992) The 48-kDa subunit of the mammalian oligosaccharyltransferase complex is homologous to the essential yeast protein WBP1. J Biol Chem. 267(33): 23658-63.
2. Fu J, et al. (1997) Interactions among subunits of the oligosaccharyltransferase complex. J Biol Chem. 272(47): 29687-92.
3. Yamagata T, et al. (1997) Genomics. Genome organization of human 48-kDa oligosaccharyltransferase (DDOST). 45(3): 535-40.
4. Fu J, et al. (2000) Retention of subunits of the oligosaccharyltransferase complex in the endoplasmic reticulum. J Biol Chem. 275(6): 3984-90.
5. Hardt B, et al. (2001) Analysis of structural signals conferring localisation of pig OST48 to the endoplasmic reticulum. Biol Chem. 382(7): 1039-47.