<p>The soluble ligand-binding beta-grasp domain (SLBB) contains a beta-grasp fold. They are found in a diverse set of proteins that include the animal vitamin B12 uptake proteins; transcobalamin, intrinsic factor and the bacterial polysaccharide export proteins [<cite idref="PUB00044948"/>]. Some proteins may be part of a membrane complex involved in electron transport, others are probably involved in the export of the extracellular polysaccharide colanic acid from the cell to medium.</p>