STT3A_PONAB
ID STT3A_PONAB Reviewed; 705 AA.
AC Q5RCE2;
DT 08-APR-2008, integrated into UniProtKB/Swiss-Prot.
DT 21-DEC-2004, sequence version 1.
DT 03-AUG-2022, entry version 69.
DE RecName: Full=Dolichyl-diphosphooligosaccharide--protein glycosyltransferase subunit STT3A {ECO:0000250|UniProtKB:P46977};
DE Short=Oligosaccharyl transferase subunit STT3A;
DE Short=STT3-A;
DE EC=2.4.99.18;
GN Name=STT3A {ECO:0000250|UniProtKB:P46977};
OS Pongo abelii (Sumatran orangutan) (Pongo pygmaeus abelii).
OC Eukaryota; Metazoa; Chordata; Craniata; Vertebrata; Euteleostomi; Mammalia;
OC Eutheria; Euarchontoglires; Primates; Haplorrhini; Catarrhini; Hominidae;
OC Pongo.
OX NCBI_TaxID=9601;
RN [1]
RP NUCLEOTIDE SEQUENCE [LARGE SCALE MRNA].
RC TISSUE=Kidney;
RG The German cDNA consortium;
RL Submitted (NOV-2004) to the EMBL/GenBank/DDBJ databases.
CC -!- FUNCTION: Catalytic subunit of the oligosaccharyl transferase (OST)
CC complex that catalyzes the initial transfer of a defined glycan
CC (Glc(3)Man(9)GlcNAc(2) in eukaryotes) from the lipid carrier dolichol-
CC pyrophosphate to an asparagine residue within an Asn-X-Ser/Thr
CC consensus motif in nascent polypeptide chains, the first step in
CC protein N-glycosylation (By similarity). N-glycosylation occurs
CC cotranslationally and the complex associates with the Sec61 complex at
CC the channel-forming translocon complex that mediates protein
CC translocation across the endoplasmic reticulum (ER). All subunits are
CC required for a maximal enzyme activity. This subunit contains the
CC active site and the acceptor peptide and donor lipid-linked
CC oligosaccharide (LLO) binding pockets (By similarity). STT3A is present
CC in the majority of OST complexes and mediates cotranslational N-
CC glycosylation of most sites on target proteins, while STT3B-containing
CC complexes are required for efficient post-translational glycosylation
CC and mediate glycosylation of sites that have been skipped by STT3A (By
CC similarity). {ECO:0000250|UniProtKB:F1PJP5,
CC ECO:0000250|UniProtKB:P39007, ECO:0000250|UniProtKB:P46977}.
CC -!- CATALYTIC ACTIVITY:
CC Reaction=a dolichyl diphosphooligosaccharide + L-asparaginyl-[protein]
CC = a dolichyl diphosphate + H(+) + N(4)-(oligosaccharide-(1->4)-N-
CC acetyl-beta-D-glucosaminyl-(1->4)-N-acetyl-beta-D-glucosaminyl)-L-
CC asparaginy-[protein]; Xref=Rhea:RHEA:22980, Rhea:RHEA-COMP:9529,
CC Rhea:RHEA-COMP:12635, Rhea:RHEA-COMP:12804, Rhea:RHEA-COMP:12805,
CC ChEBI:CHEBI:15378, ChEBI:CHEBI:50347, ChEBI:CHEBI:57497,
CC ChEBI:CHEBI:57570, ChEBI:CHEBI:132529; EC=2.4.99.18;
CC Evidence={ECO:0000250|UniProtKB:P39007};
CC -!- COFACTOR:
CC Name=Mg(2+); Xref=ChEBI:CHEBI:18420;
CC Evidence={ECO:0000250|UniProtKB:P46977};
CC Name=Mn(2+); Xref=ChEBI:CHEBI:29035;
CC Evidence={ECO:0000250|UniProtKB:B9KDD4};
CC -!- PATHWAY: Protein modification; protein glycosylation.
CC {ECO:0000250|UniProtKB:P46977}.
CC -!- SUBUNIT: Component of the oligosaccharyltransferase (OST) complex. OST
CC exists in two different complex forms which contain common core
CC subunits RPN1, RPN2, OST48, OST4, DAD1 and TMEM258, either STT3A or
CC STT3B as catalytic subunits, and form-specific accessory subunits (By
CC similarity). STT3A complex assembly occurs through the formation of 3
CC subcomplexes. Subcomplex 1 contains RPN1 and TMEM258, subcomplex 2
CC contains the STT3A-specific subunits STT3A, DC2/OSTC, and KCP2 as well
CC as the core subunit OST4, and subcomplex 3 contains RPN2, DAD1, and
CC OST48. The STT3A complex can form stable complexes with the Sec61
CC complex or with both the Sec61 and TRAP complexes.
CC {ECO:0000250|UniProtKB:F1PJP5, ECO:0000250|UniProtKB:P46977}.
CC -!- SUBCELLULAR LOCATION: Endoplasmic reticulum membrane
CC {ECO:0000250|UniProtKB:P46978}; Multi-pass membrane protein
CC {ECO:0000250|UniProtKB:P46978}.
CC -!- DOMAIN: Despite low primary sequence conservation between eukaryotic
CC catalytic subunits and bacterial and archaeal single subunit OSTs
CC (ssOST), structural comparison revealed several common motifs at
CC spatially equivalent positions, like the DXD motif 1 on the external
CC loop 1 and the DXD motif 2 on the external loop 2 involved in binding
CC of the metal ion cofactor and the carboxamide group of the acceptor
CC asparagine, the conserved Glu residue of the TIXE/SVSE motif on the
CC external loop 5 involved in catalysis, as well as the WWDYG and the
CC DK/MI motifs in the globular domain that define the binding pocket for
CC the +2 Ser/Thr of the acceptor sequon. In bacterial ssOSTs, an Arg
CC residue was found to interact with a negatively charged side chain at
CC the -2 position of the sequon. This Arg is conserved in bacterial
CC enzymes and correlates with an extended sequon requirement (Asp-X-Asn-
CC X-Ser/Thr) for bacterial N-glycosylation.
CC {ECO:0000250|UniProtKB:P39007}.
CC -!- SIMILARITY: Belongs to the STT3 family. {ECO:0000305}.
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DR EMBL; CR858329; CAH90565.1; -; mRNA.
DR RefSeq; NP_001127302.1; NM_001133830.1.
DR AlphaFoldDB; Q5RCE2; -.
DR SMR; Q5RCE2; -.
DR CAZy; GT66; Glycosyltransferase Family 66.
DR Ensembl; ENSPPYT00000004792; ENSPPYP00000004611; ENSPPYG00000004034.
DR GeneID; 100174363; -.
DR KEGG; pon:100174363; -.
DR CTD; 3703; -.
DR GeneTree; ENSGT00940000156655; -.
DR InParanoid; Q5RCE2; -.
DR OrthoDB; 187775at2759; -.
DR UniPathway; UPA00378; -.
DR Proteomes; UP000001595; Chromosome 11.
DR GO; GO:0016021; C:integral component of membrane; IEA:UniProtKB-KW.
DR GO; GO:0035000; C:oligosaccharyltransferase III complex; ISS:UniProtKB.
DR GO; GO:0004579; F:dolichyl-diphosphooligosaccharide-protein glycotransferase activity; ISS:UniProtKB.
DR GO; GO:0046872; F:metal ion binding; IEA:UniProtKB-KW.
DR GO; GO:0043686; P:co-translational protein modification; ISS:UniProtKB.
DR GO; GO:0018279; P:protein N-linked glycosylation via asparagine; ISS:UniProtKB.
DR InterPro; IPR003674; Oligo_trans_STT3.
DR PANTHER; PTHR13872; PTHR13872; 1.
DR Pfam; PF02516; STT3; 1.
PE 2: Evidence at transcript level;
KW Endoplasmic reticulum; Glycoprotein; Glycosyltransferase; Magnesium;
KW Manganese; Membrane; Metal-binding; Reference proteome; Transferase;
KW Transmembrane; Transmembrane helix.
FT CHAIN 1..705
FT /note="Dolichyl-diphosphooligosaccharide--protein
FT glycosyltransferase subunit STT3A"
FT /id="PRO_0000326557"
FT TOPO_DOM 1..17
FT /note="Cytoplasmic"
FT /evidence="ECO:0000305"
FT TRANSMEM 18..38
FT /note="Helical"
FT /evidence="ECO:0000255"
FT TOPO_DOM 39..119
FT /note="Lumenal"
FT /evidence="ECO:0000305"
FT TRANSMEM 120..138
FT /note="Helical"
FT /evidence="ECO:0000250|UniProtKB:P39007"
FT TOPO_DOM 139..140
FT /note="Cytoplasmic"
FT /evidence="ECO:0000305"
FT TRANSMEM 141..158
FT /note="Helical"
FT /evidence="ECO:0000250|UniProtKB:P39007"
FT TOPO_DOM 159..169
FT /note="Lumenal"
FT /evidence="ECO:0000305"
FT TRANSMEM 170..189
FT /note="Helical"
FT /evidence="ECO:0000250|UniProtKB:P39007"
FT TOPO_DOM 190..191
FT /note="Cytoplasmic"
FT /evidence="ECO:0000305"
FT TRANSMEM 192..206
FT /note="Helical"
FT /evidence="ECO:0000250|UniProtKB:P39007"
FT TOPO_DOM 207..211
FT /note="Lumenal"
FT /evidence="ECO:0000305"
FT TRANSMEM 212..228
FT /note="Helical"
FT /evidence="ECO:0000250|UniProtKB:P39007"
FT TOPO_DOM 229..233
FT /note="Cytoplasmic"
FT /evidence="ECO:0000305"
FT TRANSMEM 234..259
FT /note="Helical"
FT /evidence="ECO:0000250|UniProtKB:P39007"
FT TOPO_DOM 260..267
FT /note="Lumenal"
FT /evidence="ECO:0000305"
FT TRANSMEM 268..287
FT /note="Helical"
FT /evidence="ECO:0000250|UniProtKB:P39007"
FT TOPO_DOM 288..300
FT /note="Cytoplasmic"
FT /evidence="ECO:0000305"
FT TRANSMEM 301..321
FT /note="Helical"
FT /evidence="ECO:0000255"
FT TOPO_DOM 322..356
FT /note="Lumenal"
FT /evidence="ECO:0000305"
FT TRANSMEM 357..379
FT /note="Helical"
FT /evidence="ECO:0000250|UniProtKB:P39007"
FT TOPO_DOM 380..385
FT /note="Cytoplasmic"
FT /evidence="ECO:0000305"
FT TRANSMEM 386..402
FT /note="Helical"
FT /evidence="ECO:0000250|UniProtKB:P39007"
FT TOPO_DOM 403..406
FT /note="Lumenal"
FT /evidence="ECO:0000305"
FT TRANSMEM 407..428
FT /note="Helical"
FT /evidence="ECO:0000250|UniProtKB:P39007"
FT TOPO_DOM 429..453
FT /note="Cytoplasmic"
FT /evidence="ECO:0000305"
FT TRANSMEM 454..473
FT /note="Helical"
FT /evidence="ECO:0000250|UniProtKB:P39007"
FT TOPO_DOM 474..705
FT /note="Lumenal"
FT /evidence="ECO:0000305"
FT REGION 525..527
FT /note="Interacts with target acceptor peptide in protein
FT substrate"
FT /evidence="ECO:0000250|UniProtKB:B9KDD4"
FT MOTIF 47..49
FT /note="DXD motif 1"
FT /evidence="ECO:0000250|UniProtKB:Q5HTX9"
FT MOTIF 167..169
FT /note="DXD motif 2"
FT /evidence="ECO:0000250|UniProtKB:P39007"
FT MOTIF 348..351
FT /note="SVSE motif"
FT /evidence="ECO:0000250|UniProtKB:Q5HTX9"
FT MOTIF 525..529
FT /note="WWDYG motif"
FT /evidence="ECO:0000250|UniProtKB:P39007"
FT MOTIF 592..599
FT /note="DK motif"
FT /evidence="ECO:0000250|UniProtKB:P39007"
FT BINDING 49
FT /ligand="Mn(2+)"
FT /ligand_id="ChEBI:CHEBI:29035"
FT /evidence="ECO:0000250|UniProtKB:B9KDD4"
FT BINDING 167
FT /ligand="Mn(2+)"
FT /ligand_id="ChEBI:CHEBI:29035"
FT /evidence="ECO:0000250|UniProtKB:B9KDD4"
FT BINDING 169
FT /ligand="Mn(2+)"
FT /ligand_id="ChEBI:CHEBI:29035"
FT /evidence="ECO:0000250|UniProtKB:B9KDD4"
FT BINDING 405
FT /ligand="dolichyl diphosphooligosaccharide"
FT /ligand_id="ChEBI:CHEBI:57570"
FT /evidence="ECO:0000250|UniProtKB:B9KDD4"
FT BINDING 530
FT /ligand="dolichyl diphosphooligosaccharide"
FT /ligand_id="ChEBI:CHEBI:57570"
FT /evidence="ECO:0000250|UniProtKB:B9KDD4"
FT SITE 49
FT /note="Interacts with target acceptor peptide in protein
FT substrate"
FT /evidence="ECO:0000250|UniProtKB:B9KDD4"
FT SITE 160
FT /note="Important for catalytic activity"
FT /evidence="ECO:0000250|UniProtKB:B9KDD4"
FT SITE 351
FT /note="Interacts with target acceptor peptide in protein
FT substrate"
FT /evidence="ECO:0000250|UniProtKB:B9KDD4"
FT SITE 595
FT /note="Interacts with target acceptor peptide in protein
FT substrate"
FT /evidence="ECO:0000250|UniProtKB:B9KDD4"
FT CARBOHYD 537
FT /note="N-linked (GlcNAc...) asparagine"
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00498"
FT CARBOHYD 544
FT /note="N-linked (GlcNAc...) asparagine"
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00498"
FT CARBOHYD 548
FT /note="N-linked (GlcNAc...) (high mannose) asparagine"
FT /evidence="ECO:0000250|UniProtKB:P39007"
SQ SEQUENCE 705 AA; 80530 MW; 71426CA5598B51C4 CRC64;
MTKFGFLRLS YEKQDTLLKL LILSMAAVLS FSTRLFAVLR FESVIHEFDP YFNYRTTRFL
AEEGFYKFHN WFDDRAWYPL GRIIGGTIYP GLMITSAAIY HVLHFFHITI DIRNVCVFLA
PLFSSFTTIV TYHLTKELKD AGAGLLAAAM IAVVPGYISR SVAGSYDNEG IAIFCMLLTY
YMWIKAVKTG SICWAAKCAL AYFYMVSSWG GYVFLINLIP LHVLVLMLTG RFSHRIYVAY
CTVYCLGTIL SMQISFVGFQ PVLSSEHMAA FGVFGLCQIH AFVDYLRSKL NPQQFEVLFR
SVISLVGFVL LTVGALLMLT GKISPWTGRF YSLLDPSYAK NNIPIIASVS EHQPTTWSSY
YFDLQLLVFM FPVGLYYCFS NLSDARIFII MYGVTSMYFS AVMVRLMLVL APVMCILSGI
GVSQVLSTYM KNLDISRPDK KSKKQQDSTY PIKNEVASGM ILVMAFFLIT YTFHSTWVTS
EAYSSPSIVL SARGGDGSRI IFDDFREAYY WLRHNTPEDA KVMSWWDYGY QITAMANRTI
LVDNNTWNNT HISRVGQAMA STEEKAYEIM RELDVSYVLV IFGGLTGYSS DDINKFLWMV
RIGGSTDTGK HIKENDYYTP TGEFRVDREG SPVLLNCLMY KMCYYRFGQV YTEAKRPPGF
DRVRNAEIGN KDFELDVLEE AYTTEHWLVR IYKVKDLDNR GLSRT
