Crystal structure of beta-luffin, a ribosome-inactivating protein, at 2.0 A resolution.

The crystal structure of beta-luffin at 2.0 A resolution was solved by the molecular-replacement method using polyalanyl trichosanthin as the search model. The structure was refined with CNS1.1, giving R(work) = 0.162 and R(free) = 0.204. The r.m.s.d.s of the bond lengths and bond angles are 0.008 A and 1.3 degrees, respectively. The overall structure is similar to those of other type I RIPs. Three N-acetylglucosamine (Nag) molecules are linked to residues Asn2, Asn78 and Asn85 of the protein.