Galactosylgalactosylxylosylprotein 3-beta-glucuronosyltransferase 3

UniProt data

UniProt name: B3GA3_HUMAN (O94766)

Gene name: B3GAT3

Organism: Homo sapiens (Human).

Function: Glycosaminoglycans biosynthesis (PubMed:25893793). Involved in forming the linkage tetrasaccharide present in heparan sulfate and chondroitin sulfate. Transfers a glucuronic acid moiety from the uridine diphosphate-glucuronic acid (UDP-GlcUA) to the common linkage region trisaccharide Gal-beta-1,3-Gal-beta-1,4- Xyl covalently bound to a Ser residue at the glycosaminylglycan attachment site of proteoglycans. Can also play a role in the biosynthesis of l2/HNK-1 carbohydrate epitope on glycoproteins. Shows strict specificity for Gal-beta-1,3-Gal-beta-1,4-Xyl, exhibiting negligible incorporation into other galactoside substrates including Galbeta1-3Gal beta1-O-benzyl, Galbeta1- 4GlcNAc and Galbeta1-4Glc. Stimulates 2-phosphoxylose phosphatase activity of PXYLP1 in presence of uridine diphosphate-glucuronic acid (UDP-GlcUA) during completion of linkage region formation (PubMed:24425863). {ECO:0000269|PubMed:24425863, ECO:0000269|PubMed:25893793}.

Subcellular location: Golgi apparatus membrane {ECO:0000269|PubMed:21763480}; Single-pass type II membrane protein {ECO:0000269|PubMed:21763480}. Golgi apparatus, cis-Golgi network {ECO:0000269|PubMed:21763480, ECO:0000269|PubMed:25893793}.

Transmembrane domains:

  1. 8-28, 21 AA, Helical; Signal-anchor for type II membrane protein. {ECO:0000255}.

Sequence: 335 AA

10 20 30 40 50 60 MKLKLKNVFL AYFLVSIAGL LYALVQLGQP CDCLPPLRAA AEQLRQKDLR ISQLQAELRR 70 80 90 100 110 120 PPPAPAQPPE PEALPTIYVV TPTYARLVQK AELVRLSQTL SLVPRLHWLL VEDAEGPTPL 130 140 150 160 170 180 VSGLLAASGL LFTHLVVLTP KAQRLREGEP GWVHPRGVEQ RNKALDWLRG RGGAVGGEKD 190 200 210 220 230 240 PPPPGTQGVV YFADDDNTYS RELFEEMRWT RGVSVWPVGL VGGLRFEGPQ VQDGRVVGFH 250 260 270 280 290 300 TAWEPSRPFP VDMAGFAVAL PLLLDKPNAQ FDSTAPRGHL ESSLLSHLVD PKDLEPRAAN 310 320 330 CTRVLVWHTR TEKPKMKQEE QLQRQGRGSD PAIEV

CATM prediction

The sequence of B3GA3_HUMAN returned 1 potential models

The positions at the dimer's interface are highlighted in yellow. The position at the crossing point is highlighted in orange.

# Sequence and interface d θ Z' ω' Score
       10        20        30
+    |    +    |    +    | 		 (Å) (°) (Å) (°)  
Model 1 LKNVFLAYFLVSIAGLLYALVQLGQAC 7.3 -51.0° 2.4 45.1 -7.6
Prolines* LKNVFLAYFLVSIAGLLYALVQLGQPC          

* Note: this sequence contains Pro residues. CATM substituted them with Ala during the modeling. The positions are marked.

Click on the model number to visualize its details below.

MODEL 1 DETAILS

Precited structure:


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Download model 1 structure: PDB, PyMOL session

List of hydrogen bonds:

Donor Acceptor Distance
B, 16, SER, HA A, 15, VAL, O 3.46Å
B, 19, GLY, HA1 A, 16, SER, O 3.23Å
A, 16, SER, HA B, 15, VAL, O 3.46Å
A, 19, GLY, HA1 B, 16, SER, O 3.23Å