AtFXG1, an Arabidopsis gene encoding alpha-L-fucosidase active against fucosylated xyloglucan oligosaccharides.
An alpha-L-fucosidase (EC 3.2.1.51) able to release the t-fucosyl residue from the side chain of xyloglucan oligosaccharides has been detected in the leaves of Arabidopsis plants. Moreover, an alpha-L-fucosidase with similar substrate specificity was purified from cabbage (Brassica oleracea) leaves to render a single band on SDS-PAGE. Two peptide sequences were obtained from this protein band, and they were used to identify an Arabidopsis gene coding for an alpha-fucosidase that we propose to call AtFXG1. In addition, an Arabidopsis gene with homology with known alpha-L-fucosidases has been also found, and we proposed to name it as AtFUC1. Both AtFXG1 and ATFUC1 were heterologously expressed in Pichia pastoris cells and the alpha-L-fucosidase activities secreted to the culture medium. The alpha-L-fucosidase encoded by AtFXG1 was active against the oligosaccharides from xyloglucan XXFG as well as against 2'-fucosyl-lactitol but not against p-nitrophenyl-alpha-L-fucopyranoside. However, the AtFUC1 heterologously expressed was active only against 2'-fucosyl-lactitol. Thus, the former must be related to xyloglucan metabolism.
de La Torre
Francisco
F
Departamento de Biología Vegetal, Laboratorio de Fisiología Vegetal, Facultad de Biología, Universidad de Santiago de Compostela, E-15782 Santiago de Compostela, Spain.
Sampedro
Javier
J
Zarra
Ignacio
I
Revilla
Gloria
G
D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000201:enzymology* / Q000235:genetics; D001937:Brassica / Q000201:enzymology* / Q000235:genetics; D015971:Gene Expression Regulation, Enzymologic; D005936:Glucans; D006027:Glycosides / Q000378:metabolism; D008969:Molecular Sequence Data; D018515:Plant Leaves / Q000201:enzymology* / Q000235:genetics; D011134:Polysaccharides / Q000378:metabolism*; D017386:Sequence Homology, Amino Acid; D013379:Substrate Specificity; D014990:Xylans; D005644:alpha-L-Fucosidase / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*
D005936:Glucans; D006027:Glycosides; D011134:Polysaccharides; D014990:Xylans; C014125:4-nitrophenylfucoside; C029353:xyloglucan; D005644:alpha-L-Fucosidase