3.2.1.46 | crystal structures of GALC and the GALC-D-galactose product complex, to 2.1 and 2.4 A resolution, respectively. The overall fold comprises a central triosephosphate isomerase barrel, a beta-sandwich domain, and a lectin domain. The overall fold of GALC is unchanged upon galactose binding, the core of the binding pocket being formed by the long loops on the C-terminal face of the TIM barrel. Loops from both the beta-sandwich and lectin domains also contribute to the substrate-binding pocket, and mutations involved in Krabbe's disease are widely distributed throughout the protein |