Structural highlights
Function
BGL42_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 PubMed
Plants 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 Also
References
- ↑ Zamioudis C, Hanson J, Pieterse CM. β-Glucosidase BGLU42 is a MYB72-dependent key regulator of rhizobacteria-induced systemic resistance and modulates iron deficiency responses in Arabidopsis roots. New Phytol. 2014 Oct;204(2):368-79. PMID:25138267 doi:10.1111/nph.12980
- ↑ Horikoshi S, Saburi W, Yu J, Matsuura H, Cairns JRK, Yao M, Mori H. Substrate specificity of glycoside hydrolase family 1 β-glucosidase AtBGlu42 from Arabidopsis thaliana and its molecular mechanism. Biosci Biotechnol Biochem. 2022 Jan 24;86(2):231-245. PMID:34965581 doi:10.1093/bbb/zbab200
- ↑ Horikoshi S, Saburi W, Yu J, Matsuura H, Cairns JRK, Yao M, Mori H. Substrate specificity of glycoside hydrolase family 1 β-glucosidase AtBGlu42 from Arabidopsis thaliana and its molecular mechanism. Biosci Biotechnol Biochem. 2022 Jan 24;86(2):231-245. PMID:34965581 doi:10.1093/bbb/zbab200
