Disaccharides permeases: constituents of xylanolytic and mannanolytic systems of Aureobasidium pullulans.
Aureobasidium pullulans, a yeast-like microorganism was found to produce mannobiose permease and xylobiose permease, transporting beta-1,4-mannobiose or beta-1,4-xylobiose into the cells from extracellular media. Both permeases are induced by the same inducers as the corresponding hemicellulolytic enzyme systems. Mannobiose permease is induced by beta-1,4-mannobiose or is formed in the cells growing on mannan (inducers of beta-mannanolytic enzymes) and xylobiose permease is induced by d-xylose, beta-1,4-xylobiose or during the growth on xylan (inducers of xylanolytic enzymes). The permeases are energy dependent, synthesized de novo and their activities are inhibited by d-glucose. Since mannobiose permease transports beta-1,4-mannobiose, xylobiose permease appears to be less specific and transports beta-1,4-mannobiose, beta-1,4-xylobiose and methyl beta-d-xylopyranoside. Methyl beta-d-mannopyranoside or methyl beta-d-xylopyranoside serve as less efficient inducers of the corresponding permeases than beta-1,4-mannobiose or beta-1, 4-xylobiose.
Lubomír
K
K
Institute of Chemistry, Slovak Academy of Sciences, Dúbravská cesta 9, 842 38 Bratislava, Slovak Republic. chemkrem@savba.sk
Peter
B
B
D004187:Disaccharides / Q000378:metabolism*; D008351:Mannans / Q000378:metabolism*; D008361:Mannosidases / Q000096:biosynthesis; D026901:Membrane Transport Proteins / Q000096:biosynthesis*; D003904:Mitosporic Fungi / Q000201:enzymology*; D011134:Polysaccharides / Q000378:metabolism; D013379:Substrate Specificity; D014995:Xylosidases / Q000096:biosynthesis
D004187:Disaccharides; D008351:Mannans; D026901:Membrane Transport Proteins; D011134:Polysaccharides; C014647:mannobiose; C007916:hemicellulose; D008361:Mannosidases; D014995:Xylosidases; C004173:xylobiose