RRC ID 50763
Author Jung JH, Kim MJ, Jeong WS, Seo DH, Ha SJ, Kim YW, Park CS.
Title Characterization of divergent pseudo-sucrose isomerase from Azotobacter vinelandii: Deciphering the absence of sucrose isomerase activity.
Journal Biochem Biophys Res Commun
Abstract Among members of the glycoside hydrolase (GH) family, sucrose isomerase (SIase) and oligo-1,6-glucosidase (O16G) are evolutionarily closely related even though their activities show different specificities. A gene (Avin_08330) encoding a putative SIase (AZOG: Azotobacterglucocosidase) from the nitrogen-fixing bacterium Azotobacter vinelandii is a type of pseudo-SIase harboring the "RLDRD" motif, a SIase-specific region in 329-333. However, neither sucrose isomerization nor hydrolysis activities were observed in recombinant AZOG (rAZOG). The rAZOG showed similar substrate specificity to Bacillus O16G as it catalyzes the hydrolysis of isomaltulose and isomaltose, which contain α-1,6-glycosidic linkages. Interestingly, rAZOG could generate isomaltose from the small substrate methyl-α-glucoside (MαG) via intermolecular transglycosylation. In addition, sucrose isomers isomaltulose and trehalulose were produced when 250 mM fructose was added to the MαG reaction mixture. The conserved regions I and II of AZOG are shared with many O16Gs, while regions III and IV are very similar to those of SIases. Strikingly, a shuffled AZOG, in which the N-terminal region of SIase containing conserved regions I and II was exchanged with the original enzyme, exhibited a production of sucrose isomers. This study demonstrates an evolutionary relationship between SIase and O16G and suggests some of the main regions that determine the specificity of SIase and O16G.
Volume 483(1)
Pages 115-121
Published 2017-1-29
DOI 10.1016/j.bbrc.2016.12.184
PII S0006-291X(16)32256-2
PMID 28042032
MeSH Amino Acid Motifs Azotobacter vinelandii / enzymology* Azotobacter vinelandii / genetics Bacterial Proteins / chemistry Bacterial Proteins / genetics Bacterial Proteins / metabolism* Biotechnology Catalytic Domain Conserved Sequence Disaccharides / metabolism Evolution, Molecular Genes, Bacterial Genetic Variation Glucosyltransferases / chemistry Glucosyltransferases / genetics Glucosyltransferases / metabolism* Isomaltose / analogs & derivatives Isomaltose / metabolism Models, Molecular Oligo-1,6-Glucosidase / chemistry Oligo-1,6-Glucosidase / genetics Oligo-1,6-Glucosidase / metabolism Phylogeny Recombinant Proteins / chemistry Recombinant Proteins / genetics Recombinant Proteins / metabolism Sequence Homology, Amino Acid Substrate Specificity Sucrose / metabolism
IF 2.985
Times Cited 1
General Microbes JCM 9153