... substituted by an alanine. The arabinanaseactivity of the mutants D3 8A, D17 1A and E22 4A wasassayed in an Escherichia coli periplasmic fraction and compared to that of the wild-type (WT). Under theseconditions, ... and de-branched arabinans, and heteropolysaccharidessuch as arabinoxylans and arabinogalactans. Arabinanis composed of a- 1,5-linked l-arabinofuranosyl units,some of which are substituted with a- 1,3- ... poly-saccharides that includes xylans, arabinans, galactans,mannans and glucans. l-arabinose, the second mostabundant pentose in nature, is found in significantamounts in homopolysaccharides, branched and de-branched...