Preliminary crystallographic characterization of ricin agglutinin

✍ Scribed by E. C. Sweeney; A. G. Tonevitsky; D. E. Temiakov; I. I. Agapov; S. Saward; R. A. Palmer

• Book ID: 101228796
• Publisher: John Wiley and Sons
• Year: 1997
• Tongue: English
• Weight: 128 KB
• Volume: 28
• Category: Article
• ISSN: 0887-3585
• DOI: 10.1002/(sici)1097-0134(199708)28:4<586::aid-prot12>3.0.co;2-c

✦ Synopsis

The quaternary structure of ricin agglutinin (RCA) has been determined by x-ray crystallography. The refined structure of ricin proved to be a successful search model using the molecular replacement method of phase determination. RCA forms an elongated molecule of dimensions 120 A x 60 A x 40 A with two A chains at the center and a B chain at each end. The A chains are covalently associated via a disulfide bridge between Cys 156 of both chains. Additional contacts at residues 114-5 stabilize the dimer interface. The covalent association of RCAA chains was confirmed by gel filtration under reducing and nonreducing conditions.