OST5/YGL226C-A Summary Help

OST5 BASIC INFORMATION

Standard Name OST5 1
Systematic Name YGL226C-A
Feature Type ORF, Verified
Description Zeta subunit of the oligosaccharyltransferase complex of the ER lumen, which catalyzes asparagine-linked glycosylation of newly synthesized proteins (1, 2 and see Summary Paragraph)
Name Description OligoSaccharylTransferase 1
GO Annotations All OST5 GO evidence and references
    View Computational GO annotations for OST5
Molecular Function
Manually curated
Biological Process
Manually curated
Cellular Component
Manually curated
Mutant Phenotype All OST5 Phenotype details and references
Large-scale survey
null
Interactions OST5 All interactions details and references
74 total interaction(s) for 33 unique genes/features.
Physical Interactions
  • Affinity Capture-MS: 1
  • Affinity Capture-RNA: 1
  • Affinity Capture-Western: 9
  • Co-purification: 2
  • Two-hybrid: 4
Genetic Interactions
  • Dosage Rescue: 1
  • Phenotypic Enhancement: 36
  • Phenotypic Suppression: 12
  • Synthetic Growth Defect: 3
  • Synthetic Lethality: 5
Sequence Information
ChrVII:73157 to 72748 | ORF Map | GBrowse
Note: this feature is encoded on the Crick strand.
Gbrowse
Last Update Coordinates: 2004-07-15 | Sequence: 1996-07-31
Subfeature details
Relative
Coordinates		 Chromosomal
Coordinates		 Most Recent Updates
Coordinates Sequence
CDS 1..21 73157..73137 2004-07-15 1996-07-31
Intron 22..170 73136..72988 2004-07-15 1996-07-31
CDS 171..410 72987..72748 2004-07-15 1996-07-31
External Links All Associated Seq | E.C. | Entrez Gene | Entrez RefSeq Protein | MIPS | UniProtKB
Primary SGDIDS000003194

OST5 RESOURCES

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SGD ORF mapGBrowse
SGD ORF map
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  • Sequence Analysis Tools
  • Protein Info & Structure
  • Localization Resources
  • Interactions
  • Phenotype Resources
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  • Comparison Resources
  • Functional Analysis

Click on histogram for expression summary
Expression Summary histogram

ADDITIONAL INFORMATION for OST5

SUMMARY PARAGRAPH for OST5

During N-linked glycosylation of proteins, oligosaccharide chains are assembled on the carrier molecule dolichyl pyrophosphate in the following order: 2 molecules of N-acetylglucosamine (GlcNAc), 9 molecules of mannose, and 3 molecules of glucose. These 14-residue oligosaccharide cores are then transferred to asparagine residues on nascent polypeptide chains in the endoplasmic reticulum (ER). As proteins progress through the Golgi apparatus, the oligosaccharide cores are modified by trimming and extension to generate a diverse array of glycosylated proteins (reviewed in 3, 4).

The oligosaccharyl transferase complex (OST complex) (EC 2.4.1.119) transfers 14-sugar branched oligosaccharides from dolichyl pyrophosphate to asparagine residues. The complex contains nine protein subunits: Ost1p, Ost2p, Ost3p, Ost4p, Ost5p, Ost6p, Stt3p, Swp1p, and Wbp1p, all of which are integral membrane proteins of the ER. The OST complex interacts with the Sec61p pore complex (5) involved in protein import into the ER.

One of the original six OST complex subunits purified (6), Ost5p was eventually identified as the 9.5 kDa zeta subunit (1) in a synthetic lethal screen in alg5 mutant cells. Individually, deletions of either OST5 or ALG5 have only mild phenotypes, but deletion of both confers a synthetic temperature-sensitive (ts) glycosylation defect at 30° C (1).

Last updated: 2005-07-12

REFERENCES CITED ON THIS PAGE [View Complete Literature Guide for OST5]

1) Reiss G, et al.  (1997) A specific screen for oligosaccharyltransferase mutations identifies the 9 kDa OST5 protein required for optimal activity in vivo and in vitro. EMBO J 16(6):1164-72
2) Knauer R and Lehle L  (1999) The oligosaccharyltransferase complex from yeast. Biochim Biophys Acta 1426(2):259-73
3) Herscovics A and Orlean P  (1993) Glycoprotein biosynthesis in yeast. FASEB J 7(6):540-50
4) Burda P and Aebi M  (1999) The dolichol pathway of N-linked glycosylation. Biochim Biophys Acta 1426(2):239-57
5) Chavan M, et al.  (2005) Subunits of the translocon interact with components of the oligosaccharyl transferase complex. J Biol Chem 280(24):22917-24
6) Kelleher DJ and Gilmore R  (1994) The Saccharomyces cerevisiae oligosaccharyltransferase is a protein complex composed of Wbp1p, Swp1p, and four additional polypeptides. J Biol Chem 269(17):12908-17