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l ‐Arabinose transport and catabolism in yeast
Author(s) -
Fonseca César,
Romão Rute,
Rodrigues de Sousa Helena,
HahnHägerdal Bärbel,
SpencerMartins Isabel
Publication year - 2007
Publication title -
the febs journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.981
H-Index - 204
eISSN - 1742-4658
pISSN - 1742-464X
DOI - 10.1111/j.1742-4658.2007.05892.x
Subject(s) - catabolism , biochemistry , arabinose , yeast , cofactor , metabolism , enzyme , pichia , biology , chemistry , fermentation , gene , pichia pastoris , xylose , recombinant dna
Two yeasts, Candida arabinofermentans PYCC 5603 T and Pichia guilliermondii PYCC 3012, which show rapid growth on l ‐arabinose and very high rates of l ‐arabinose uptake on screening, were selected for characterization of l ‐arabinose transport and the first steps of intracellular l ‐arabinose metabolism. The kinetics of l ‐arabinose uptake revealed at least two transport systems with distinct substrate affinities, specificities, functional mechanisms and regulatory properties. The l ‐arabinose catabolic pathway proposed for filamentous fungi also seems to operate in the yeasts studied. The kinetic parameters of the initial l ‐arabinose‐metabolizing enzymes were determined. Reductases were found to be mostly NADPH‐dependent, whereas NAD was the preferred cofactor of dehydrogenases. The differences found between the two yeasts agree with the higher efficiency of l ‐ arabinose metabolism in C. arabinofermentans . This is the first full account of the initial steps of l ‐arabinose catabolism in yeast including the biochemical characterization of a specific l ‐ arabinose transporter.