InterPro domain: IPR008979

Proteins containing a galactose-binding-like domain fold can be found in several different protein families, in both eukaryotes and prokaryotes. The common function of these domains is to bind to specific ligands, such as cell-surface-attached carbohydrate substrates for galactose oxidase and sialidase [ 1 ], phospholipids on the outer side of the mammalian cell membrane for coagulation factor Va [ 2 ], membrane-anchored ephrin for the Eph family of receptor tyrosine kinases [ 3 ], and a complex of broken single-stranded DNA and DNA polymerase beta for XRCC1 [ 4 ].

The structure of the galactose-binding-like domain members consists of a beta-sandwich, in which the strands making up the sheets exhibit a jellyroll fold. There is a high degree of similarity in the beta-sandwich and in the loops between different family members, despite an often low level of sequence similarity.

1. Novel thioether bond revealed by a 1.7 A crystal structure of galactose oxidase. Nature 350, 87-90
2. Crystal structures of the membrane-binding C2 domain of human coagulation factor V. Nature 402, 434-9
3. Crystal structure of an Eph receptor-ephrin complex. Nature 414, 933-8
4. Solution structure of the single-strand break repair protein XRCC1 N-terminal domain. Nat. Struct. Biol. 6, 884-93