This is a delta4,5-anhydrogalacturonic acid-specific carbohydrate-binding module family 35, which is found in several prokaryotic proteins. Its crystal structure shows a jelly roll/beta-sandwich fold with 2 antiparallel sheets made of 4 and 5 antiparallel beta-strands [1]. It is also found at the end of a family of putative glycosyl hydrolases.

1: Evidence that family 35 carbohydrate binding modules display conserved specificity but divergent function. Montanier C, van Bueren AL, Dumon C, Flint JE, Correia MA, Prates JA, Firbank SJ, Lewis RJ, Grondin GG, Ghinet MG, Gloster TM, Herve C, Knox JP, Talbot BG, Turkenburg JP, Kerovuo J, Brzezinski R, Fontes CM, Davies GJ, Boraston AB, Gilbert HJ; Proc Natl Acad Sci U S A. 2009;106:3065-3070. PMID:19218457