| Structural highlights
7jhk is a 4 chain structure with sequence from Human. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
| | Ligands: | , , , , |
| Gene: | B3GNT2, B3GALT7, B3GNT1 (HUMAN) |
| Activity: | N-acetyllactosaminide beta-1,3-N-acetylglucosaminyltransferase, with EC number 2.4.1.149 |
| Resources: | FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT |
Function
[B3GN2_HUMAN] Beta-1,3-N-acetylglucosaminyltransferase involved in the synthesis of poly-N-acetyllactosamine. Catalyzes the initiation and elongation of poly-N-acetyllactosamine chains. Shows a marked preference for Gal(beta1-4)Glc(NAc)-based acceptors (PubMed:9892646). Probably constitutes the main polylactosamine synthase.[1] [2] [3]
Publication Abstract from PubMed
beta1,3-N-acetylglucosaminyltransferases (B3GNTs) are Golgi-resident glycosyltransferases involved in the biosynthesis of poly-N-acetyl-lactosamine chains. They catalyze the addition of the N-acetylglucosamine to the N-acetyl-lactosamine repeat as a key step of the chain elongation process. Poly-N-acetyl-lactosamine is involved in immune system in many ways. Particularly, its long chain has been demonstrated to suppress excessive immune responses. Among the characterized B3GNTs, B3GNT2 is the major poly-N-acetyl-lactosamine synthase and deletion of its coding gene dramatically reduced the cell surface poly-N-acetyl-lactosamine and led to hypersensitive and hyperresponsive immunocytes. Despite the extensive functional studies, no structural information is available to understand the molecular mechanism of B3GNT2, as well as other B3GNTs. Here we present the structural and kinetic studies of the human B3GNT2. Five crystal structures of B3GNT2 have been determined in the unliganded, donor substrate-bound, acceptor substrate-bound and product(s)-bound states at resolutions ranging from 1.85 A to 2.35 A. Kinetic study shows that the transglycosylation reaction follows a sequential mechanism. Critical residues involved in recognition of both donor and acceptor substrates as well as catalysis are identified. Mutations of these invariant residues impair B3GNT2 activity in cell assays. Structural comparison with other glycosyltransferases such as mouse Fringe reveals a novel N-terminal helical domain of B3GNTs that may stabilize the catalytic domain and distinguish among different acceptor substrates.
Structures and mechanism of human glycosyltransferase beta1,3-N-acetylglucosaminyltransferase 2 (B3GNT2), an important player in immune homeostasis.,Hao Y, Crequer-Grandhomme A, Javier N, Singh A, Chen H, Manzanillo P, Lo MC, Huang X J Biol Chem. 2020 Nov 6. pii: RA120.015306. doi: 10.1074/jbc.RA120.015306. PMID:33158990[4]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Shiraishi N, Natsume A, Togayachi A, Endo T, Akashima T, Yamada Y, Imai N, Nakagawa S, Koizumi S, Sekine S, Narimatsu H, Sasaki K. Identification and characterization of three novel beta 1,3-N-acetylglucosaminyltransferases structurally related to the beta 1,3-galactosyltransferase family. J Biol Chem. 2001 Feb 2;276(5):3498-507. doi: 10.1074/jbc.M004800200. Epub 2000, Oct 19. PMID:11042166 doi:http://dx.doi.org/10.1074/jbc.M004800200
- ↑ Praissman JL, Live DH, Wang S, Ramiah A, Chinoy ZS, Boons GJ, Moremen KW, Wells L. B4GAT1 is the priming enzyme for the LARGE-dependent functional glycosylation of alpha-dystroglycan. Elife. 2014 Oct 3;3. doi: 10.7554/eLife.03943. PMID:25279697 doi:http://dx.doi.org/10.7554/eLife.03943
- ↑ Zhou D, Dinter A, Gutierrez Gallego R, Kamerling JP, Vliegenthart JF, Berger EG, Hennet T. A beta-1,3-N-acetylglucosaminyltransferase with poly-N-acetyllactosamine synthase activity is structurally related to beta-1,3-galactosyltransferases. Proc Natl Acad Sci U S A. 1999 Jan 19;96(2):406-11. doi: 10.1073/pnas.96.2.406. PMID:9892646 doi:http://dx.doi.org/10.1073/pnas.96.2.406
- ↑ Hao Y, Crequer-Grandhomme A, Javier N, Singh A, Chen H, Manzanillo P, Lo MC, Huang X. Structures and mechanism of human glycosyltransferase beta1,3-N-acetylglucosaminyltransferase 2 (B3GNT2), an important player in immune homeostasis. J Biol Chem. 2020 Nov 6. pii: RA120.015306. doi: 10.1074/jbc.RA120.015306. PMID:33158990 doi:http://dx.doi.org/10.1074/jbc.RA120.015306
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