7f3a
From Proteopedia
Arabidopsis thaliana GH1 beta-glucosidase AtBGlu42
Structural highlights
FunctionBGL42_ARATH Glucosidase that hydrolyzes scopolin and various beta-glucosides, cellooligosaccharides (mainly cellotriose) and laminarioligosaccharides (PubMed:34965581). Can use p-nitrophenyl-beta-glucosides (pNP beta-Glc) and p-nitrophenyl-beta-D-fucosides (pNP beta-D-Fuc) as substrates, and, to a lower extent, beta-galactosides, beta-mannosides and beta-xylosides (PubMed:34965581). Involved in the secretion of root-derived phenolics upon iron ions (Fe) depletion (PubMed:25138267). Promotes disease resistance toward B.cinerea, H.arabidopsidis and P.syringae pv. tomato DC3000 (PubMed:25138267). Required during rhizobacteria-mediated (e.g. P.fluorescens WCS417r) broad-spectrum induced systemic resistance (ISR) against several pathogens (PubMed:25138267).[1] [2] Publication Abstract from PubMedPlants possess many glycoside hydrolase family 1 (GH1) beta-glucosidases, which physiologically function in cell wall metabolism and activation of bioactive substances, but most remain uncharacterized. One GH1 isoenzyme AtBGlu42 in Arabidopsis thaliana has been identified to hydrolyze scopolin using the gene deficient plants, but no enzymatic properties were obtained. Its sequence similarity to another functionally characterized enzyme Os1BGlu4 in rice suggests that AtBGlu42 also acts on oligosaccharides. Here, we show that the recombinant AtBGlu42 possesses high kcat/Km not only on scopolin, but also on various beta-glucosides, cellooligosaccharides, and laminarioligosaccharides. Of the cellooligosaccharides, cellotriose was the most preferred. The crystal structure, determined at 1.7 A resolution, suggests that Arg342 gives unfavorable binding to cellooligosaccharides at subsite +3. The mutants R342Y and R342A showed the highest preference on cellotetraose or cellopentaose with increased affinities at subsite +3, indicating that the residues at this position have an important role for chain length specificity. Substrate specificity of glycoside hydrolase family 1 beta-glucosidase AtBGlu42 from Arabidopsis thaliana and its molecular mechanism.,Horikoshi S, Saburi W, Yu J, Matsuura H, Cairns JRK, Yao M, Mori H Biosci Biotechnol Biochem. 2022 Jan 24;86(2):231-245. doi: 10.1093/bbb/zbab200. PMID:34965581[3] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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