Table 1 Summary of activity assays on different substrates

Cellulose and cello-oligosaccharides

++

Activity on both cellulose oligosaccharides and insoluble cellulose material (PASC)

++

Activity on both cellulose oligosaccharides and insoluble cellulose material (PASC)

MLG

++

Pattern suggests β-(1 → 3) bonds accommodated at specific places within active site, but not between −1 and +1

++

Pattern suggests β-(1 → 3) bonds accommodated at specific places within active site, but not between −1 and +1

Glucomannan and Man₆

++

Cleavage can occur with Glc or mannose at −1 or +1. Inactivity on Man₆ indicates some Glc C2 hydroxyl orientation needs to be present between −3 and +3

++

Cleavage can occur with Glc or mannose at −1 or +1. Inactivity on Man₆ indicates some Glc C2 hydroxyl orientation needs to be present between −3 and +3

Xyloglucan

++

Cleavage occurs with unsubstituted Glc at subsite +1. Xylosyl substitution at −3, −2, −1, +2 and +3. Galactosyl-xylosyl substitutions can occur at either −2, −1 and/or +3

++

Cleavage occurs with unsubstituted Glc at subsite +1. Xylosyl substitution at −3, −2, −1, +2 and +3. Galactosyl-xylosyl substitutions can occur at either −2, −1 and/or +3

Xylan and Xyl₆

+

Activity on both. Weak Xyl₆ activity compared to Cell₆ suggests that, while Glc C6 is not required for activity, it is very important at certain sites, such as +1

+/–

Much poorer activity of CvAA9A compared with LsAA9A

Starch

–

Absence of activity indicates that LsAA9A necessarily cleaves β-(1 → 4) bonds

–

Absence of activity indicates that CvAA9A necessarily cleaves β-(1 → 4) bonds

Laminarin

–

–

G4G3G4G (MLG oligosaccharide)

–

–

Chitin

–

Absence of activity indicates that LsAA9A either requires O2 interactions or cannot accommodate N-acetyl on amino C2

–

Absence of activity indicates that CvAA9A either requires O2 interactions or cannot accommodate N-acetyl on amino C2