8X3Q

tll1591 with alpha-glucan 4sugar

Summary for 8X3Q

• Entry DOI: 10.2210/pdb8x3q/pdb
• Descriptor: Glycosyl transferase, alpha-D-glucopyranose-(1-2)-alpha-D-glucopyranose-(1-2)-alpha-D-glucopyranose-(1-2)-beta-D-fructofuranose, URIDINE-5'-DIPHOSPHATE, ... (4 entities in total)
• Functional Keywords: tll1591 with alpha-glucan 4sugar, transferase
• Biological source: Thermosynechococcus vestitus (strain NIES-2133 / IAM M-273 / BP-1)
• Total number of polymer chains: 4
• Total formula weight: 158670.39

Authors

Su, J.Y. (deposition date: 2023-11-14, release date: 2024-10-16, Last modification date: 2025-04-30)

Primary citation

Qu, X.,An, Q.,Sayed, H.,Cui, L.,Mayo, K.H.,Su, J.Y.
Glucosyltransferase TeGSS from Thermosynechococcus elongatus produces an alpha-1,2-glucan.
Int.J.Biol.Macromol., 280:136152-136152, 2024

PubMed Abstract: Here, we enzymatically produced a novel α-1,2-glucan, glucosylsucrose, that has a chemical structure significantly different from that of other glucans. This structural difference suggests its potential to modulate new physiological activities compared to known glucans. The enzyme TeGSS catalyzes the synthesis of this α-1,2-glucan from sucrose and UDP-glucose (UDPG). Using NMR spectroscopy, we elucidated the chemical structures of TeGSS-synthesized glucosylsucrose tri-, tetra-, and penta-saccharides in which the monosaccharide units are linked by α-1,2-glycosidic bonds. We also report the crystal structures of TeGSS co-crystallized with UDP and glucosylsucrose tri- and tetra-saccharides. Site-directed mutagenesis of residues in and around the TeGSS catalytic center has allowed us to propose a concerted Si mechanism of action. Finally, we developed an enzyme-coupled reaction involving TeGSS and SuSyAc that allows production of UDPG for the synthesis of α-1,2-glucan.

PubMed: 39357710
DOI: 10.1016/j.ijbiomac.2024.136152

Experimental method

X-RAY DIFFRACTION (2.66 Å)