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Protein

Dolichyl-diphosphooligosaccharide--protein glycosyltransferase subunit STT3B

Gene

STT3B

Organism
Homo sapiens (Human)
Status
Reviewed-Annotation score: Annotation score: 5 out of 5-Experimental evidence at protein leveli

Functioni

Catalytic subunit of the N-oligosaccharyl transferase (OST) complex which catalyzes the transfer of a high mannose oligosaccharide from a lipid-linked oligosaccharide donor 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). STT3B is present in a small subset of OST complexes and mediates both cotranslational and post-translational N-glycosylation of target proteins: STT3B-containing complexes are required for efficient cotranslational glycosylation and while they are less competent than STT3A-containing complexes for cotranslational glycosylation, they have the ability to mediate glycosylation of some nascent sites that are not accessible for STT3A. STT3B-containing complexes also act post-translationally and mediate modification of skipped glycosylation sites in unfolded proteins. Plays a role in ER-associated degradation (ERAD) pathway that mediates ubiquitin-dependent degradation of misfolded endoplasmic reticulum proteins by mediating N-glycosylation of unfolded proteins, which are then recognized by the ERAD pathway and targeted for degradation. Mediates glycosylation of the disease variant AMYL-TTR 'Asp-38' of TTR at 'Asn-118', leading to its degradation.2 Publications

Catalytic activityi

Dolichyl diphosphooligosaccharide + [protein]-L-asparagine = dolichyl diphosphate + a glycoprotein with the oligosaccharide chain attached by N-beta-D-glycosyl linkage to a protein L-asparagine.

Pathwayi: protein glycosylation

This protein is involved in the pathway protein glycosylation, which is part of Protein modification.
View all proteins of this organism that are known to be involved in the pathway protein glycosylation and in Protein modification.

GO - Molecular functioni

  • dolichyl-diphosphooligosaccharide-protein glycotransferase activity Source: UniProtKB

GO - Biological processi

  • co-translational protein modification Source: UniProtKB
  • ER-associated ubiquitin-dependent protein catabolic process Source: UniProtKB
  • glycoprotein catabolic process Source: UniProtKB
  • post-translational protein modification Source: UniProtKB
  • protein N-linked glycosylation via asparagine Source: UniProtKB
  • response to unfolded protein Source: UniProtKB
Complete GO annotation...

Keywords - Molecular functioni

Glycosyltransferase, Transferase

Enzyme and pathway databases

BioCyciZFISH:HS08872-MONOMER.
SignaLinkiQ8TCJ2.
UniPathwayiUPA00378.

Protein family/group databases

CAZyiGT66. Glycosyltransferase Family 66.

Names & Taxonomyi

Protein namesi
Recommended name:
Dolichyl-diphosphooligosaccharide--protein glycosyltransferase subunit STT3B (EC:2.4.99.18)
Short name:
Oligosaccharyl transferase subunit STT3B
Short name:
STT3-B
Alternative name(s):
Source of immunodominant MHC-associated peptides homolog
Gene namesi
Name:STT3B
Synonyms:SIMP
OrganismiHomo sapiens (Human)
Taxonomic identifieri9606 [NCBI]
Taxonomic lineageiEukaryotaMetazoaChordataCraniataVertebrataEuteleostomiMammaliaEutheriaEuarchontogliresPrimatesHaplorrhiniCatarrhiniHominidaeHomo
Proteomesi
  • UP000005640 Componenti: Chromosome 3

Organism-specific databases

HGNCiHGNC:30611. STT3B.

Subcellular locationi

Topology

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Topological domaini2 – 64CytoplasmicSequence analysisAdd BLAST63
Transmembranei65 – 85HelicalSequence analysisAdd BLAST21
Topological domaini86 – 168LumenalSequence analysisAdd BLAST83
Transmembranei169 – 189HelicalSequence analysisAdd BLAST21
Topological domaini190 – 223CytoplasmicSequence analysisAdd BLAST34
Transmembranei224 – 244HelicalSequence analysisAdd BLAST21
Topological domaini245 – 262LumenalSequence analysisAdd BLAST18
Transmembranei263 – 283HelicalSequence analysisAdd BLAST21
Topological domaini284 – 291CytoplasmicSequence analysis8
Transmembranei292 – 312HelicalSequence analysisAdd BLAST21
Topological domaini313 – 319LumenalSequence analysis7
Transmembranei320 – 340HelicalSequence analysisAdd BLAST21
Topological domaini341 – 351CytoplasmicSequence analysisAdd BLAST11
Transmembranei352 – 372HelicalSequence analysisAdd BLAST21
Topological domaini373 – 410LumenalSequence analysisAdd BLAST38
Transmembranei411 – 431HelicalSequence analysisAdd BLAST21
Topological domaini432 – 440CytoplasmicSequence analysis9
Transmembranei441 – 461HelicalSequence analysisAdd BLAST21
Topological domaini462 – 463LumenalSequence analysis2
Transmembranei464 – 484HelicalSequence analysisAdd BLAST21
Topological domaini485 – 537CytoplasmicSequence analysisAdd BLAST53
Transmembranei538 – 558HelicalSequence analysisAdd BLAST21
Topological domaini559 – 826LumenalSequence analysisAdd BLAST268

GO - Cellular componenti

Complete GO annotation...

Keywords - Cellular componenti

Endoplasmic reticulum, Membrane

Pathology & Biotechi

Involvement in diseasei

Congenital disorder of glycosylation 1X (CDG1X)1 Publication
The disease is caused by mutations affecting the gene represented in this entry.
Disease descriptionA form of congenital disorder of glycosylation, a multisystem disorder caused by a defect in glycoprotein biosynthesis and characterized by under-glycosylated serum glycoproteins. Congenital disorders of glycosylation result in a wide variety of clinical features, such as defects in the nervous system development, psychomotor retardation, dysmorphic features, hypotonia, coagulation disorders, and immunodeficiency. The broad spectrum of features reflects the critical role of N-glycoproteins during embryonic development, differentiation, and maintenance of cell functions.
See also OMIM:615597

Keywords - Diseasei

Congenital disorder of glycosylation

Organism-specific databases

DisGeNETi201595.
MalaCardsiSTT3B.
MIMi615597. phenotype.
OpenTargetsiENSG00000163527.
Orphaneti370924. STT3B-CDG.
PharmGKBiPA143485625.

Polymorphism and mutation databases

BioMutaiSTT3B.
DMDMi74715800.

PTM / Processingi

Molecule processing

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Initiator methionineiRemovedCombined sources
ChainiPRO_00002460012 – 826Dolichyl-diphosphooligosaccharide--protein glycosyltransferase subunit STT3BAdd BLAST825

Amino acid modifications

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Modified residuei2N-acetylalanineCombined sources1
Modified residuei13PhosphoserineBy similarity1
Modified residuei18PhosphoserineCombined sources1
Modified residuei29PhosphoserineCombined sources1
Glycosylationi161N-linked (GlcNAc...)Sequence analysis1
Modified residuei498PhosphoserineCombined sources1
Modified residuei499PhosphoserineCombined sources1
Glycosylationi616N-linked (GlcNAc...)Sequence analysis1
Glycosylationi623N-linked (GlcNAc...)1 Publication1
Glycosylationi627N-linked (GlcNAc...)1 Publication1
Glycosylationi641N-linked (GlcNAc...)Sequence analysis1

Keywords - PTMi

Acetylation, Glycoprotein, Phosphoprotein

Proteomic databases

EPDiQ8TCJ2.
MaxQBiQ8TCJ2.
PaxDbiQ8TCJ2.
PeptideAtlasiQ8TCJ2.
PRIDEiQ8TCJ2.

PTM databases

iPTMnetiQ8TCJ2.
PhosphoSitePlusiQ8TCJ2.
SwissPalmiQ8TCJ2.

Expressioni

Tissue specificityi

Expressed in heart, brain, placenta, lung, liver, muscle, kidney and pancreas. Expressed in skin fibroblasts (at protein level).1 Publication

Gene expression databases

BgeeiENSG00000163527.
CleanExiHS_STT3B.
GenevisibleiQ8TCJ2. HS.

Organism-specific databases

HPAiHPA036448.
HPA036646.

Interactioni

Subunit structurei

Component of the oligosaccharyltransferase (OST) complex (By similarity). OST seems to exist in different forms which contain at least RPN1, RPN2, OST48, DAD1, OSTC, KRTCAP2 and either STT3A or STT3B. OST can form stable complexes with the Sec61 complex or with both the Sec61 and TRAP complexes.By similarity2 Publications

Protein-protein interaction databases

BioGridi128394. 36 interactors.
IntActiQ8TCJ2. 25 interactors.
STRINGi9606.ENSP00000295770.

Structurei

3D structure databases

ProteinModelPortaliQ8TCJ2.
ModBaseiSearch...
MobiDBiSearch...

Family & Domainsi

Sequence similaritiesi

Belongs to the STT3 family.Curated

Keywords - Domaini

Transmembrane, Transmembrane helix

Phylogenomic databases

eggNOGiKOG2292. Eukaryota.
COG1287. LUCA.
GeneTreeiENSGT00390000015238.
HOGENOMiHOG000157471.
HOVERGENiHBG010606.
InParanoidiQ8TCJ2.
KOiK07151.
OMAiXYIAPWS.
OrthoDBiEOG091G02DB.
PhylomeDBiQ8TCJ2.
TreeFamiTF300822.

Family and domain databases

InterProiIPR003674. Oligo_trans_STT3.
[Graphical view]
PfamiPF02516. STT3. 1 hit.
[Graphical view]

Sequencei

Sequence statusi: Complete.

Sequence processingi: The displayed sequence is further processed into a mature form.

Q8TCJ2-1 [UniParc]FASTAAdd to basket

« Hide

        10         20         30         40         50
MAEPSAPESK HKSSLNSSPW SGLMALGNSR HGHHGPGAQC AHKAAGGAAP
60 70 80 90 100
PKPAPAGLSG GLSQPAGWQS LLSFTILFLA WLAGFSSRLF AVIRFESIIH
110 120 130 140 150
EFDPWFNYRS THHLASHGFY EFLNWFDERA WYPLGRIVGG TVYPGLMITA
160 170 180 190 200
GLIHWILNTL NITVHIRDVC VFLAPTFSGL TSISTFLLTR ELWNQGAGLL
210 220 230 240 250
AACFIAIVPG YISRSVAGSF DNEGIAIFAL QFTYYLWVKS VKTGSVFWTM
260 270 280 290 300
CCCLSYFYMV SAWGGYVFII NLIPLHVFVL LLMQRYSKRV YIAYSTFYIV
310 320 330 340 350
GLILSMQIPF VGFQPIRTSE HMAAAGVFAL LQAYAFLQYL RDRLTKQEFQ
360 370 380 390 400
TLFFLGVSLA AGAVFLSVIY LTYTGYIAPW SGRFYSLWDT GYAKIHIPII
410 420 430 440 450
ASVSEHQPTT WVSFFFDLHI LVCTFPAGLW FCIKNINDER VFVALYAISA
460 470 480 490 500
VYFAGVMVRL MLTLTPVVCM LSAIAFSNVF EHYLGDDMKR ENPPVEDSSD
510 520 530 540 550
EDDKRNQGNL YDKAGKVRKH ATEQEKTEEG LGPNIKSIVT MLMLMLLMMF
560 570 580 590 600
AVHCTWVTSN AYSSPSVVLA SYNHDGTRNI LDDFREAYFW LRQNTDEHAR
610 620 630 640 650
VMSWWDYGYQ IAGMANRTTL VDNNTWNNSH IALVGKAMSS NETAAYKIMR
660 670 680 690 700
TLDVDYVLVI FGGVIGYSGD DINKFLWMVR IAEGEHPKDI RESDYFTPQG
710 720 730 740 750
EFRVDKAGSP TLLNCLMYKM SYYRFGEMQL DFRTPPGFDR TRNAEIGNKD
760 770 780 790 800
IKFKHLEEAF TSEHWLVRIY KVKAPDNRET LDHKPRVTNI FPKQKYLSKK
810 820
TTKRKRGYIK NKLVFKKGKK ISKKTV
Length:826
Mass (Da):93,674
Last modified:June 1, 2002 - v1
Checksum:iB70C221C7CBEB798
GO

Sequence cautioni

The sequence AAH15880 differs from that shown. Reason: Erroneous initiation. Translation N-terminally extended.Curated
The sequence BAB55370 differs from that shown. Reason: Erroneous initiation. Translation N-terminally extended.Curated
The sequence BAC11581 differs from that shown. Reason: Erroneous initiation. Translation N-terminally extended.Curated

Experimental Info

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Sequence conflicti822S → F in AAH15880 (PubMed:15489334).Curated1

Sequence databases

Select the link destinations:
EMBLi
GenBanki
DDBJi
Links Updated
AY074880 mRNA. Translation: AAL71884.1.
AC104643 Genomic DNA. No translation available.
AK027789 mRNA. Translation: BAB55370.1. Different initiation.
AK075380 mRNA. Translation: BAC11581.1. Different initiation.
BC015880 mRNA. Translation: AAH15880.1. Different initiation.
CCDSiCCDS2650.1.
RefSeqiNP_849193.1. NM_178862.2.
UniGeneiHs.475812.

Genome annotation databases

EnsembliENST00000295770; ENSP00000295770; ENSG00000163527.
GeneIDi201595.
KEGGihsa:201595.
UCSCiuc011axe.3. human.

Cross-referencesi

Sequence databases

Select the link destinations:
EMBLi
GenBanki
DDBJi
Links Updated
AY074880 mRNA. Translation: AAL71884.1.
AC104643 Genomic DNA. No translation available.
AK027789 mRNA. Translation: BAB55370.1. Different initiation.
AK075380 mRNA. Translation: BAC11581.1. Different initiation.
BC015880 mRNA. Translation: AAH15880.1. Different initiation.
CCDSiCCDS2650.1.
RefSeqiNP_849193.1. NM_178862.2.
UniGeneiHs.475812.

3D structure databases

ProteinModelPortaliQ8TCJ2.
ModBaseiSearch...
MobiDBiSearch...

Protein-protein interaction databases

BioGridi128394. 36 interactors.
IntActiQ8TCJ2. 25 interactors.
STRINGi9606.ENSP00000295770.

Protein family/group databases

CAZyiGT66. Glycosyltransferase Family 66.

PTM databases

iPTMnetiQ8TCJ2.
PhosphoSitePlusiQ8TCJ2.
SwissPalmiQ8TCJ2.

Polymorphism and mutation databases

BioMutaiSTT3B.
DMDMi74715800.

Proteomic databases

EPDiQ8TCJ2.
MaxQBiQ8TCJ2.
PaxDbiQ8TCJ2.
PeptideAtlasiQ8TCJ2.
PRIDEiQ8TCJ2.

Protocols and materials databases

Structural Biology KnowledgebaseSearch...

Genome annotation databases

EnsembliENST00000295770; ENSP00000295770; ENSG00000163527.
GeneIDi201595.
KEGGihsa:201595.
UCSCiuc011axe.3. human.

Organism-specific databases

CTDi201595.
DisGeNETi201595.
GeneCardsiSTT3B.
HGNCiHGNC:30611. STT3B.
HPAiHPA036448.
HPA036646.
MalaCardsiSTT3B.
MIMi608605. gene.
615597. phenotype.
neXtProtiNX_Q8TCJ2.
OpenTargetsiENSG00000163527.
Orphaneti370924. STT3B-CDG.
PharmGKBiPA143485625.
GenAtlasiSearch...

Phylogenomic databases

eggNOGiKOG2292. Eukaryota.
COG1287. LUCA.
GeneTreeiENSGT00390000015238.
HOGENOMiHOG000157471.
HOVERGENiHBG010606.
InParanoidiQ8TCJ2.
KOiK07151.
OMAiXYIAPWS.
OrthoDBiEOG091G02DB.
PhylomeDBiQ8TCJ2.
TreeFamiTF300822.

Enzyme and pathway databases

UniPathwayiUPA00378.
BioCyciZFISH:HS08872-MONOMER.
SignaLinkiQ8TCJ2.

Miscellaneous databases

GeneWikiiSTT3B.
GenomeRNAii201595.
PROiQ8TCJ2.
SOURCEiSearch...

Gene expression databases

BgeeiENSG00000163527.
CleanExiHS_STT3B.
GenevisibleiQ8TCJ2. HS.

Family and domain databases

InterProiIPR003674. Oligo_trans_STT3.
[Graphical view]
PfamiPF02516. STT3. 1 hit.
[Graphical view]
ProtoNetiSearch...

Entry informationi

Entry nameiSTT3B_HUMAN
AccessioniPrimary (citable) accession number: Q8TCJ2
Secondary accession number(s): Q96JZ4, Q96KY7
Entry historyi
Integrated into UniProtKB/Swiss-Prot: July 11, 2006
Last sequence update: June 1, 2002
Last modified: November 2, 2016
This is version 113 of the entry and version 1 of the sequence. [Complete history]
Entry statusiReviewed (UniProtKB/Swiss-Prot)
Annotation programChordata Protein Annotation Program
DisclaimerAny medical or genetic information present in this entry is provided for research, educational and informational purposes only. It is not in any way intended to be used as a substitute for professional medical advice, diagnosis, treatment or care.

Miscellaneousi

Keywords - Technical termi

Complete proteome, Reference proteome

Documents

  1. Human chromosome 3
    Human chromosome 3: entries, gene names and cross-references to MIM
  2. MIM cross-references
    Online Mendelian Inheritance in Man (MIM) cross-references in UniProtKB/Swiss-Prot
  3. PATHWAY comments
    Index of metabolic and biosynthesis pathways
  4. SIMILARITY comments
    Index of protein domains and families

Similar proteinsi

Links to similar proteins from the UniProt Reference Clusters (UniRef) at 100%, 90% and 50% sequence identity:
100%UniRef100 combines identical sequences and sub-fragments with 11 or more residues from any organism into one UniRef entry.
90%UniRef90 is built by clustering UniRef100 sequences that have at least 90% sequence identity to, and 80% overlap with, the longest sequence (a.k.a seed sequence).
50%UniRef50 is built by clustering UniRef90 seed sequences that have at least 50% sequence identity to, and 80% overlap with, the longest sequence in the cluster.