2gdu | pdb_00002gdu
E232Q mutant of sucrose phosphorylase from BIFIDOBACTERIUM ADOLESCENTIS in complex with sucrose
Structural highlights
FunctionSUCP_BIFAA Catalyzes the reversible phosphorolysis of sucrose into alpha-D-glucose 1-phosphate (Glc1P) and D-fructose (PubMed:14740189, PubMed:20691225). Is involved in sucrose degradation. Also displays transglucosylation activity in vitro, by transferring the glucosyl moiety of Glc1P to a broad range of monomeric sugars, such as D- and L-arabinose, D- and L-arabitol, and xylitol (PubMed:14740189).[1] [2] Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedThe reaction mechanism of sucrose phosphorylase from Bifidobacterium adolescentis (BiSP) was studied by site-directed mutagenesis and x-ray crystallography. An inactive mutant of BiSP (E232Q) was co-crystallized with sucrose. The structure revealed a substrate-binding mode comparable with that seen in other related sucrose-acting enzymes. Wild-type BiSP was also crystallized in the presence of sucrose. In the dimeric structure, a covalent glucosyl intermediate was formed in one molecule of the BiSP dimer, and after hydrolysis of the glucosyl intermediate, a beta-D-glucose product complex was formed in the other molecule. Although the overall structure of the BiSP-glucosyl intermediate complex is similar to that of the BiSP(E232Q)-sucrose complex, the glucose complex discloses major differences in loop conformations. Two loops (residues 336-344 and 132-137) in the proximity of the active site move up to 16 and 4 A, respectively. On the basis of these findings, we have suggested a reaction cycle that takes into account the large movements in the active-site entrance loops. Structural rearrangements of sucrose phosphorylase from Bifidobacterium adolescentis during sucrose conversion.,Mirza O, Skov LK, Sprogoe D, van den Broek LA, Beldman G, Kastrup JS, Gajhede M J Biol Chem. 2006 Nov 17;281(46):35576-84. Epub 2006 Sep 21. PMID:16990265[3] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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