Abstract
The x-ray crystallographic structure of the heterodimeric plant toxin ricin has been determined at 2.8-A resolution. The A chain enzyme is a globular protein with extensive secondary structure and a reasonably prominent cleft assumed to be the active site. The B chain lectin folds into two topologically similar domains, each binding lactose in a shallow cleft. In each site a glutamine residue forms a hydrogen bond to the OH-4 of galactose, accounting for the epimerimic specificity of binding. The interface between the A and B chains shows some hydrophobic contacts in which proline and phenylalanine side chains play a prominent role.
Original language | English (US) |
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Pages (from-to) | 5398-5403 |
Number of pages | 6 |
Journal | Journal of Biological Chemistry |
Volume | 262 |
Issue number | 11 |
State | Published - Apr 15 1987 |
ASJC Scopus subject areas
- Biochemistry
- Molecular Biology
- Cell Biology