Members of this family are carbohydrate binding modules that bind to beta-1, 4-manno-oligosaccharides, carob galactomannan, and konjac glucomannan, but not to cellulose (insoluble and soluble) or soluble birchwood xylan. They adopt a beta sandwich structure comprising 13 beta strands with a single, small alpha-helix and a single metal atom [1].

1: Structural and thermodynamic dissection of specific mannan recognition by a carbohydrate binding module, TmCBM27. Boraston AB, Revett TJ, Boraston CM, Nurizzo D, Davies GJ; Structure. 2003;11:665-675. PMID:12791255