Q99380 (OST4_YEAST) Reviewed, UniProtKB/Swiss-Prot

Names and origin

Protein names

Recommended name:
Dolichyl-diphosphooligosaccharide--protein glycosyltransferase subunit OST4
Short name=Oligosaccharyl transferase subunit OST4
EC=2.4.1.119

Alternative name(s):
Oligosaccharyl transferase 4 kDa subunit
Short name=OTase 4 kDa subunit

Gene names

Name:	OST4
Ordered Locus Names:	YDL232W

Organism

Saccharomyces cerevisiae (strain ATCC 204508 / S288c) (Baker's yeast)

Taxonomic identifier

559292 [NCBI]

Taxonomic lineage

Eukaryota › Fungi › Dikarya › Ascomycota › Saccharomycotina › Saccharomycetes › Saccharomycetales › Saccharomycetaceae › Saccharomyces

Protein attributes

Sequence length	36 AA.
Sequence status	Complete.
Protein existence	Evidence at protein level

General annotation (Comments)

Function	Essential subunit of N-oligosaccharyl transferase enzyme which catalyzes the transfer of a high mannose oligosaccharide to an asparagine residue within an Asn-X-Ser/Thr consensus motif in nascent polypeptide chains. N-glycosylation occurs cotranslationally and the complex associates with the Sec61 complex at the channel-forming translocon complex that mediates protein translocation across the endoplasmic reticulum (ER). All subunits are required for a maximal enzyme activity. OST4 is required for recruitment of OST3 or OST6 to the OST complex. It is essential for cell growth at 37 but not at 25 degrees Celsius.
Catalytic activity	Dolichyl diphosphooligosaccharide + protein L-asparagine = dolichyl diphosphate + a glycoprotein with the oligosaccharide chain attached by N-glycosyl linkage to protein L-asparagine.
Pathway	Protein modification; protein glycosylation.
Subunit structure	Component of the oligosaccharyl transferase (OST) complex, which apears to exist in two assemblies comprising OST1, OST2, OST4, OST5, STT3, SWP1, WPB1, and either OST3 or OST6. OST3, OST4 and STT3 probably form a subcomplex. May interact directly with OST2, OST3, OST5, OST6, STT3, WBP1 and SWP1. Interacts with SEC61, SBH1 and SSS1. Ref.5 Ref.7 Ref.13 Ref.14
Subcellular location	Endoplasmic reticulum membrane; Single-pass membrane protein.
Miscellaneous	Present with 2430 molecules/cell in log phase SD medium. Ref.8

Ontologies

Keywords
Cellular component	Endoplasmic reticulum Membrane
Domain	Transmembrane Transmembrane helix
Molecular function	Transferase
Technical term	3D-structure Complete proteome Reference proteome
Gene Ontology (GO)
Biological process	protein N-linked glycosylation Inferred from mutant phenotype Ref.1. Source: UniProtKB
Cellular component	integral to membrane Inferred from electronic annotation. Source: UniProtKB-KW oligosaccharyltransferase complex Inferred from direct assay Ref.1. Source: UniProtKB
Molecular function	dolichyl-diphosphooligosaccharide-protein glycotransferase activity Inferred from mutant phenotype Ref.1. Source: UniProtKB protein binding, bridging Inferred from direct assay Ref.9. Source: SGD
Complete GO annotation...

Binary interactions

With	Entry	#Exp.	IntAct	Notes
OST3	P48439	2	EBI-12689,EBI-12680
SBH1	P52870	2	EBI-12689,EBI-16410
SEC61	P32915	2	EBI-12689,EBI-16400
SSS1	P35179	2	EBI-12689,EBI-16406

Sequence annotation (Features)

Feature key

Position(s)

Length

Description

Graphical view

Feature identifier

Molecule processing

Chain

1 – 36

36

Dolichyl-diphosphooligosaccharide--protein glycosyltransferase subunit OST4

PRO_0000058093

Regions

Topological domain

1 – 9

9

Lumenal Ref.9

Transmembrane

10 – 28

19

Helical

Topological domain

29 – 36

8

Cytoplasmic Ref.9

Experimental info

Mutagenesis

18

1

M → K: Severe growth defect; abolishes interaction with OST3 and STT3. Ref.7 Ref.9

Mutagenesis

18

1

M → L: No effect on interaction between OST3 and STT3. Ref.7 Ref.9

Mutagenesis

19

1

M → K: Severe growth defect; abolishes interaction with OST3. Ref.7 Ref.9

Mutagenesis

19

1

M → L: Disrupts interaction between OST3 and STT3. Ref.7 Ref.9

Mutagenesis

20

1

T → D: Severe growth defect. Ref.7 Ref.9

Mutagenesis

20

1

T → K: Severe growth defect; abolishes interaction with OST3; disrupts interaction between OST3 and STT3. Ref.7 Ref.9

Mutagenesis

21

1

L → K: Abolishes interaction with OST3 and STT3; disrupts interaction between OST3 and STT3. Ref.7 Ref.9

Mutagenesis

23

1

V → D: Severe growth defect. Ref.7 Ref.9

Mutagenesis

23

1

V → K: Severe growth defect; abolishes interaction with OST3; disrupts interaction between OST3 and STT3. Ref.7 Ref.9

Mutagenesis

24

1

I → D: Severe growth defect. Ref.7 Ref.9

Mutagenesis

24

1

I → K: Disrupts interaction between OST3 and STT3. Ref.7 Ref.9

Mutagenesis

25

1

Y → D: Severe growth defect. Ref.7

Secondary structure

1

.

.

.

.

36

Helix Strand Turn

Details...

Helix

6 – 8

3

Helix

9 – 28

20

Sequences

	Sequence		Length	Mass (Da)
	Q99380 [UniParc]. Last modified November 1, 1996. Version 1. Checksum: BA14A9C3B197F12A	FASTA	36	3,985
	10 20 30 MISDEQLNSL AITFGIVMMT LIVIYHAVDS TMSPKN

References

	« Hide 'large scale' referencesShow 'large scale' references »
[1]	"The OST4 gene of Saccharomyces cerevisiae encodes an unusually small protein required for normal levels of oligosaccharyltransferase activity." Chi J.H., Roos J., Dean N. J. Biol. Chem. 271:3132-3140(1996) [PubMed: 8621712] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [GENOMIC DNA]. Strain: NDY21.
[2]	"The nucleotide sequence of Saccharomyces cerevisiae chromosome IV." Jacq C., Alt-Moerbe J., Andre B., Arnold W., Bahr A., Ballesta J.P.G., Bargues M., Baron L., Becker A., Biteau N., Bloecker H., Blugeon C., Boskovic J., Brandt P., Brueckner M., Buitrago M.J., Coster F., Delaveau T. , del Rey F., Dujon B., Eide L.G., Garcia-Cantalejo J.M., Goffeau A., Gomez-Peris A., Granotier C., Hanemann V., Hankeln T., Hoheisel J.D., Jaeger W., Jimenez A., Jonniaux J.-L., Kraemer C., Kuester H., Laamanen P., Legros Y., Louis E.J., Moeller-Rieker S., Monnet A., Moro M., Mueller-Auer S., Nussbaumer B., Paricio N., Paulin L., Perea J., Perez-Alonso M., Perez-Ortin J.E., Pohl T.M., Prydz H., Purnelle B., Rasmussen S.W., Remacha M.A., Revuelta J.L., Rieger M., Salom D., Saluz H.P., Saiz J.E., Saren A.-M., Schaefer M., Scharfe M., Schmidt E.R., Schneider C., Scholler P., Schwarz S., Soler-Mira A., Urrestarazu L.A., Verhasselt P., Vissers S., Voet M., Volckaert G., Wagner G., Wambutt R., Wedler E., Wedler H., Woelfl S., Harris D.E., Bowman S., Brown D., Churcher C.M., Connor R., Dedman K., Gentles S., Hamlin N., Hunt S., Jones L., McDonald S., Murphy L.D., Niblett D., Odell C., Oliver K., Rajandream M.A., Richards C., Shore L., Walsh S.V., Barrell B.G., Dietrich F.S., Mulligan J.T., Allen E., Araujo R., Aviles E., Berno A., Carpenter J., Chen E., Cherry J.M., Chung E., Duncan M., Hunicke-Smith S., Hyman R.W., Komp C., Lashkari D., Lew H., Lin D., Mosedale D., Nakahara K., Namath A., Oefner P., Oh C., Petel F.X., Roberts D., Schramm S., Schroeder M., Shogren T., Shroff N., Winant A., Yelton M.A., Botstein D., Davis R.W., Johnston M., Andrews S., Brinkman R., Cooper J., Ding H., Du Z., Favello A., Fulton L., Gattung S., Greco T., Hallsworth K., Hawkins J., Hillier L.W., Jier M., Johnson D., Johnston L., Kirsten J., Kucaba T., Langston Y., Latreille P., Le T., Mardis E., Menezes S., Miller N., Nhan M., Pauley A., Peluso D., Rifkin L., Riles L., Taich A., Trevaskis E., Vignati D., Wilcox L., Wohldman P., Vaudin M., Wilson R., Waterston R., Albermann K., Hani J., Heumann K., Kleine K., Mewes H.-W., Zollner A., Zaccaria P. Nature 387:75-78(1997) [PubMed: 9169867] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA]. Strain: ATCC 204508 / S288c.
[3]	Saccharomyces Genome Database Submitted (DEC-2009) to the EMBL/GenBank/DDBJ databases Cited for: GENOME REANNOTATION. Strain: ATCC 204508 / S288c.
[4]	"The Saccharomyces cerevisiae oligosaccharyltransferase is a protein complex composed of Wbp1p, Swp1p, and four additional polypeptides." Kelleher D.J., Gilmore R. J. Biol. Chem. 269:12908-12917(1994) [PubMed: 8175708] [Abstract] Cited for: IDENTIFICATION IN THE OLIGOSACCHARYL TRANSFERASE COMPLEX.
[5]	"The highly conserved Stt3 protein is a subunit of the yeast oligosaccharyltransferase and forms a subcomplex with Ost3p and Ost4p." Karaoglu D., Kelleher D.J., Gilmore R. J. Biol. Chem. 272:32513-32520(1997) [PubMed: 9405463] [Abstract] Cited for: IDENTIFICATION IN THE OLIGOSACCHARYL TRANSFERASE COMPLEX, INTERACTION WITH OST3 AND STT3.
[6]	"The oligosaccharyltransferase complex from yeast." Knauer R., Lehle L. Biochim. Biophys. Acta 1426:259-273(1999) [PubMed: 9878773] [Abstract] Cited for: REVIEW ON OLIGOSACCHARYL TRANSFERASE.
[7]	"Studies on the role of the hydrophobic domain of Ost4p in interactions with other subunits of yeast oligosaccharyl transferase." Kim H., Park H., Montalvo L., Lennarz W.J. Proc. Natl. Acad. Sci. U.S.A. 97:1516-1520(2000) [PubMed: 10677492] [Abstract] Cited for: INTERACTION WITH OST3 AND STT3, MUTAGENESIS OF MET-18; MET-19; THR-20; LEU-21; VAL-23; ILE-24 AND TYR-25.
[8]	"Global analysis of protein expression in yeast." Ghaemmaghami S., Huh W.-K., Bower K., Howson R.W., Belle A., Dephoure N., O'Shea E.K., Weissman J.S. Nature 425:737-741(2003) [PubMed: 14562106] [Abstract] Cited for: LEVEL OF PROTEIN EXPRESSION [LARGE SCALE ANALYSIS].
[9]	"Determination of the membrane topology of Ost4p and its subunit interactions in the oligosaccharyltransferase complex in Saccharomyces cerevisiae." Kim H., Yan Q., Von Heijne G., Caputo G.A., Lennarz W.J. Proc. Natl. Acad. Sci. U.S.A. 100:7460-7464(2003) [PubMed: 12810948] [Abstract] Cited for: TOPOLOGY, MUTAGENESIS OF MET-18; MET-19; THR-20; LEU-21; VAL-23 AND ILE-24.
[10]	"Yeast oligosaccharyltransferase consists of two functionally distinct sub-complexes, specified by either the Ost3p or Ost6p subunit." Schwarz M., Knauer R., Lehle L. FEBS Lett. 579:6564-6568(2005) [PubMed: 16297388] [Abstract] Cited for: COMPOSITION OF THE OLIGOSACCHARYL TRANSFERASE COMPLEXES.
[11]	"The 3.4-kDa Ost4 protein is required for the assembly of two distinct oligosaccharyltransferase complexes in yeast." Spirig U., Bodmer D., Wacker M., Burda P., Aebi M. Glycobiology 15:1396-1406(2005) [PubMed: 16096346] [Abstract] Cited for: COMPOSITION OF THE OLIGOSACCHARYL TRANSFERASE COMPLEXES.
[12]	"Two oligosaccharyl transferase complexes exist in yeast and associate with two different translocons." Yan A., Lennarz W.J. Glycobiology 15:1407-1415(2005) [PubMed: 16096345] [Abstract] Cited for: COMPOSITION OF THE OLIGOSACCHARYL TRANSFERASE COMPLEXES.
[13]	"Subunits of the translocon interact with components of the oligosaccharyl transferase complex." Chavan M., Yan A., Lennarz W.J. J. Biol. Chem. 280:22917-22924(2005) [PubMed: 15831493] [Abstract] Cited for: INTERACTION WITH SEC61; SBH1 AND SSS1.
[14]	"Studies of yeast oligosaccharyl transferase subunits using the split-ubiquitin system: topological features and in vivo interactions." Yan A., Wu E., Lennarz W.J. Proc. Natl. Acad. Sci. U.S.A. 102:7121-7126(2005) [PubMed: 15886282] [Abstract] Cited for: INTERACTION WITH OST2; OST3; OST5; OST6; STT3; WBP1 AND SWP1.
[15]	"Structural basis for the function of a minimembrane protein subunit of yeast oligosaccharyltransferase." Zubkov S., Lennarz W.J., Mohanty S. Proc. Natl. Acad. Sci. U.S.A. 101:3821-3826(2004) [PubMed: 15001703] [Abstract] Cited for: STRUCTURE BY NMR, TRANSMEMBRANE DOMAIN.
+	Additional computationally mapped references.

Cross-references

Sequence databases

EMBL
GenBank
DDBJ

L42519 Genomic DNA. Translation: AAB06797.1.
Z74280 Genomic DNA. Translation: CAA98811.1.
BK006938 Genomic DNA. Translation: DAA11634.1.

PIR

S67795.

RefSeq

NP_010049.1. NM_001180292.1.

3D structure databases

PDBe
RCSB PDB
PDBj

Entry	Method	Resolution (Å)	Chain	Positions	PDBsum
1RKL	NMR	-	A	1-36	[»]

ProteinModelPortal

Q99380.

SMR

Q99380. Positions 1-36.

ModBase

Search...

Protein-protein interaction databases

DIP

DIP-2457N.

IntAct

Q99380. 7 interactions.

MINT

MINT-1357119.

STRING

Q99380.

Protocols and materials databases

StructuralBiologyKnowledgebase

Search...

Genome annotation databases

EnsemblFungi

YDL232W; YDL232W; YDL232W.

GeneID

851366.

KEGG

sce:YDL232W.

NMPDR

fig|4932.3.peg.782.

Organism-specific databases

CYGD

YDL232w.

SGD

S000002391. OST4.

Phylogenomic databases

OrthoDB

EOG4K9FP6.

Enzyme and pathway databases

BRENDA

2.4.1.119. 984.

Gene expression databases

ArrayExpress

Q99380.

Genevestigator

Q99380.

GermOnline

YDL232W. Saccharomyces cerevisiae.

Family and domain databases

InterPro

IPR018943. Oligosaccaryltransferase.
[Graphical view]

KO

K00730.

Pfam

PF10215. Ost4. 1 hit.
[Graphical view]

SUPFAM

SSF103464. Oligosaccaryltransferase. 1 hit.

ProtoNet

Search...

Other

NextBio

968480.

Entry information

Entry name

OST4_YEAST

Accession

Primary (citable) accession number: Q99380
Secondary accession number(s): D6VRC4

Entry history

Integrated into UniProtKB/Swiss-Prot:	November 1, 1997
Last sequence update:	November 1, 1996
Last modified:	November 16, 2011
This is version 91 of the entry and version 1 of the sequence. [Complete history]

Entry status

Reviewed (UniProtKB/Swiss-Prot)

Annotation program

Fungal Protein Annotation Program