UniProt functional annotation for Q3U4G3



	UniProt functional annotation for Q3U4G3

UniProt code: Q3U4G3.

Organism: Mus musculus (Mouse).

Taxonomy: Eukaryota; Metazoa; Chordata; Craniata; Vertebrata; Euteleostomi; Mammalia; Eutheria; Euarchontoglires; Glires; Rodentia; Myomorpha; Muroidea; Muridae; Murinae; Mus; Mus.

Function: Alpha-1,3-xylosyltransferase, which elongates the O-linked xylose-glucose disaccharide attached to EGF-like repeats in the extracellular domain of target proteins by catalyzing the addition of the second xylose. Known targets include Notch proteins and coagulation factors, such as F9. {ECO:0000269|PubMed:26414444}.

Catalytic activity: Reaction=3-O-[alpha-D-xylosyl-(1->3)-beta-D-glucosyl]-L-seryl-[EGF-like domain protein] + UDP-alpha-D-xylose = 3-O-[alpha-D-xylosyl-(1->3)- alpha-D-xylosyl-(1->3)-beta-D-glucosyl]-L-seryl-[EGF-like domain protein] + H(+) + UDP; Xref=Rhea:RHEA:22820, Rhea:RHEA-COMP:14611, Rhea:RHEA-COMP:14619, ChEBI:CHEBI:15378, ChEBI:CHEBI:57632, ChEBI:CHEBI:58223, ChEBI:CHEBI:140575, ChEBI:CHEBI:140599; EC=2.4.2.62; Evidence={ECO:0000269|PubMed:26414444};

Cofactor: Name=Mg(2+); Xref=ChEBI:CHEBI:18420; Evidence={ECO:0000250|UniProtKB:Q8NBI6}; Name=Mn(2+); Xref=ChEBI:CHEBI:29035; Evidence={ECO:0000305|PubMed:26414444}; Note=Has the highest in vitro activity with 20 mM Mn(2+), a concentration entirely out of the physiological range. Can also utilize Mg(2+), suggesting this may be the physiological cofactor. {ECO:0000250|UniProtKB:Q8NBI6};

Subunit: Homodimer (PubMed:26414444). Dimer formation may be essential for the retention in endoplasmic reticulum (Probable). {ECO:0000269|PubMed:26414444, ECO:0000305}.

Subcellular location: Endoplasmic reticulum membrane {ECO:0000250|UniProtKB:Q8NBI6}; Single-pass type II membrane protein {ECO:0000250|UniProtKB:Q8NBI6}.

Similarity: Belongs to the glycosyltransferase 8 family. {ECO:0000305}.

Sequence caution: Sequence=AAH31419.1; Type=Erroneous initiation; Note=Truncated N-terminus.; Evidence={ECO:0000305};

Annotations taken from UniProtKB at the EBI.


Organism:		Mus musculus (Mouse).
Taxonomy:		Eukaryota; Metazoa; Chordata; Craniata; Vertebrata; Euteleostomi; Mammalia; Eutheria; Euarchontoglires; Glires; Rodentia; Myomorpha; Muroidea; Muridae; Murinae; Mus; Mus.



Function:		Alpha-1,3-xylosyltransferase, which elongates the O-linked xylose-glucose disaccharide attached to EGF-like repeats in the extracellular domain of target proteins by catalyzing the addition of the second xylose. Known targets include Notch proteins and coagulation factors, such as F9. {ECO:0000269\|PubMed:26414444}.


Catalytic activity:		Reaction=3-O-[alpha-D-xylosyl-(1->3)-beta-D-glucosyl]-L-seryl-[EGF-like domain protein] + UDP-alpha-D-xylose = 3-O-[alpha-D-xylosyl-(1->3)- alpha-D-xylosyl-(1->3)-beta-D-glucosyl]-L-seryl-[EGF-like domain protein] + H(+) + UDP; Xref=Rhea:RHEA:22820, Rhea:RHEA-COMP:14611, Rhea:RHEA-COMP:14619, ChEBI:CHEBI:15378, ChEBI:CHEBI:57632, ChEBI:CHEBI:58223, ChEBI:CHEBI:140575, ChEBI:CHEBI:140599; EC=2.4.2.62; Evidence={ECO:0000269\|PubMed:26414444};
Cofactor:		Name=Mg(2+); Xref=ChEBI:CHEBI:18420; Evidence={ECO:0000250\|UniProtKB:Q8NBI6}; Name=Mn(2+); Xref=ChEBI:CHEBI:29035; Evidence={ECO:0000305\|PubMed:26414444}; Note=Has the highest in vitro activity with 20 mM Mn(2+), a concentration entirely out of the physiological range. Can also utilize Mg(2+), suggesting this may be the physiological cofactor. {ECO:0000250\|UniProtKB:Q8NBI6};
Subunit:		Homodimer (PubMed:26414444). Dimer formation may be essential for the retention in endoplasmic reticulum (Probable). {ECO:0000269\|PubMed:26414444, ECO:0000305}.
Subcellular location:		Endoplasmic reticulum membrane {ECO:0000250\|UniProtKB:Q8NBI6}; Single-pass type II membrane protein {ECO:0000250\|UniProtKB:Q8NBI6}.
Similarity:		Belongs to the glycosyltransferase 8 family. {ECO:0000305}.
Sequence caution:		Sequence=AAH31419.1; Type=Erroneous initiation; Note=Truncated N-terminus.; Evidence={ECO:0000305};