OST6 dolichyl-diphosphooligosaccharide--protein glycotransferase [Saccharomyces cerevisiae S288C] - Gene

Summary

Go to the top of the page Help

Official Symbol: OST6
Official Full Name: dolichyl-diphosphooligosaccharide--protein glycotransferase
Primary source: SGD:S000004481
Locus tag: YML019W
See related: AllianceGenome:SGD:S000004481; FungiDB:YML019W; VEuPathDB:YML019W
Gene type: protein coding
RefSeq status: REVIEWED
Organism: Saccharomyces cerevisiae S288C (strain: S288C)
Lineage: Eukaryota; Fungi; Dikarya; Ascomycota; Saccharomycotina; Saccharomycetes; Saccharomycetales; Saccharomycetaceae; Saccharomyces
Summary: Enables protein-disulfide reductase activity. Involved in protein N-linked glycosylation. Located in endoplasmic reticulum. Part of oligosaccharyltransferase complex. Human ortholog(s) of this gene implicated in X-linked immunodeficiency with magnesium defect, Epstein-Barr virus infection, and neoplasia; autosomal recessive intellectual developmental disorder 7; and congenital disorder of glycosylation Icc. Orthologous to human MAGT1 (magnesium transporter 1) and TUSC3 (tumor suppressor candidate 3). [provided by Alliance of Genome Resources, Jul 2025]
Orthologs: all
NEW: Try the new Gene table
Try the new Transcript table

Genomic context

Go to the top of the page Help

See OST6 in Genome Data Viewer

Location:: chromosome: XIII

Exon count:: 1

Sequence:: Chromosome: XIII; NC_001145.3 (233457..234455)

Chromosome XIII - NC_001145.3 Genomic Context describing neighboring genes

Genomic regions, transcripts, and products

Go to the top of the page Help

Go to reference sequence details

Genomic Sequence:: NC_001145.3

Go to nucleotide: Graphics FASTA GenBank

Bibliography

Go to the top of the page Help

GeneRIFs: Gene References Into Functions

What's a GeneRIF?

Substrate specificities and reaction kinetics of the yeast oligosaccharyltransferase isoforms.
Title: Substrate specificities and reaction kinetics of the yeast oligosaccharyltransferase isoforms.
OST3 and OST6 oligosaccharyltransferase subunits bind polypeptide substrate to locally enhance N-glycosylation.
Title: Oligosaccharyltransferase subunits bind polypeptide substrate to locally enhance N-glycosylation.
these assays showed that the thioredoxin-like active sites of Ost3p and Ost6p could form transient mixed disulfide bonds with cysteines in a model substrate glycoprotein, consistent with the function of Ost3p and Ost6p in modulating N-glycosylation substrate selection by OTase in vivo.
Title: Mixed disulfide formation in vitro between a glycoprotein substrate and yeast oligosaccharyltransferase subunits Ost3p and Ost6p.
Data support a model of Ost3/6p function in which they transiently bind stretches of nascent polypeptide substrate to inhibit protein folding, thereby increasing glycosylation efficiency at nearby asparagine residues.
Title: Polypeptide binding specificities of Saccharomyces cerevisiae oligosaccharyltransferase accessory proteins Ost3p and Ost6p.
Mutation of the active-site cysteine residues of Ost6p and its paralogue Ost3p affected the glycosylation efficiency of a subset of glycosylation sites.
Title: Oxidoreductase activity of oligosaccharyltransferase subunits Ost3p and Ost6p defines site-specific glycosylation efficiency.
The paralogues Ost3p and Ost6p were required for efficient glycosylation of distinct defined glycosylation sites.
Title: Analysis of glycosylation site occupancy reveals a role for Ost3p and Ost6p in site-specific N-glycosylation efficiency.
Ost4p is required for the incorporation of either Ost3p or Ost6p into the oligosaccharyltransferase complex
Title: The 3.4-kDa Ost4 protein is required for the assembly of two distinct oligosaccharyltransferase complexes in yeast.
OST consists of two isoforms with distinct functions differing only in the presence of the two related Ost3 and Ost6p proteins
Title: Yeast oligosaccharyltransferase consists of two functionally distinct sub-complexes, specified by either the Ost3p or Ost6p subunit.
Ost3p and Ost6p are similar, but do not exist in the same oligosaccharyltransferase complex: Ost3p interacts with Sbh1p, while Ost6p interacts with Sbh2p.
Title: Two oligosaccharyl transferase complexes exist in yeast and associate with two different translocons.

Submit: New GeneRIF Correction

Pathways from PubChem

Go to the top of the page

Interactions

Go to the top of the page Help

Products	Interactant	Other Gene	Complex	Source	Pubs	Description

General gene information

Go to the top of the page Help

Homology

NCBI Orthologs

Orthologs from OrthoDB

Gene Ontology Provided by SGD

Function	Evidence Code	Pubs
enables dolichyl-diphosphooligosaccharide-protein glycotransferase activity	IBA Inferred from Biological aspect of Ancestor more info
enables protein-disulfide reductase activity	IDA Inferred from Direct Assay more info	PubMed

Process	Evidence Code	Pubs
involved_in protein N-linked glycosylation	IGI Inferred from Genetic Interaction more info	PubMed
involved_in protein N-linked glycosylation via asparagine	IBA Inferred from Biological aspect of Ancestor more info
involved_in protein glycosylation	IEA Inferred from Electronic Annotation more info

Component	Evidence Code	Pubs
located_in endoplasmic reticulum	HDA more info	PubMed
located_in endoplasmic reticulum	IEA Inferred from Electronic Annotation more info
located_in endoplasmic reticulum membrane	IEA Inferred from Electronic Annotation more info
located_in endoplasmic reticulum membrane	NAS Non-traceable Author Statement more info	PubMed
located_in membrane	IEA Inferred from Electronic Annotation more info
part_of oligosaccharyltransferase complex	IBA Inferred from Biological aspect of Ancestor more info
part_of oligosaccharyltransferase complex	IDA Inferred from Direct Assay more info	PubMed
part_of oligosaccharyltransferase complex	IPI Inferred from Physical Interaction more info	PubMed

General protein information

Go to the top of the page Help

Preferred Names: dolichyl-diphosphooligosaccharide--protein glycotransferase

NP_013693.1

Subunit of the oligosaccharyltransferase complex of the ER lumen; complex catalyzes asparagine-linked glycosylation of newly synthesized proteins; similar to and partially functionally redundant with Ost3p

NCBI Reference Sequences (RefSeq)

Go to the top of the page Help

NEW Try the new Transcript table

Genome Annotation

The following sections contain reference sequences that belong to a specific genome build. Explain

Reference assembly

Genomic

NC_001145.3 Reference assembly

Range

233457..234455

Download

GenBank, FASTA, Sequence Viewer (Graphics)

mRNA and Protein(s)

NM_001182377.1 → NP_013693.1 TPA: dolichyl-diphosphooligosaccharide--protein glycotransferase

See identical proteins and their annotated locations for NP_013693.1

Status: REVIEWED

UniProtKB/Swiss-Prot

D6VZF5, E9P904, Q03723

UniProtKB/TrEMBL

A6ZM43, B3LLN3, B5VPA7, C7GLD7, G2WK33, N1NY44

Conserved Domains (1) summary

pfam04756
Location:37 → 329

OST3_OST6; OST3 / OST6 family, transporter family