title: Determination by systematic deletion of the amino acids essential for catalysis by ricin A chain.
abstract: The A chain of ricin is a RNA N-glycosidase that inactivates ribosomes by depurination of a single adenosine in 28S rRNA. Of the 267 amino acids in the protein, 222 (83%) could be deleted from one or another of 74 mutants without loss of the capacity of the protein to recognize a single nucleotide from among the 7000 in ribosomes or to catalyze hydrolysis.
authors.affiliation: Department of Biochemistry and Molecular Biology, University of Chicago, IL 60637.
authors.forename: K N
authors.initials: KN
authors.lastname: Morris
authors.forename: I G
authors.initials: IG
authors.lastname: Wool
mesh_terms: D000595:Amino Acid Sequence; D003001:Cloning, Molecular; D003196:Computer Graphics; D004252:DNA Mutational Analysis; D008958:Models, Molecular; D008969:Molecular Sequence Data; D011487:Protein Conformation; D012276:Ricin / Q000737:chemistry* / Q000378:metabolism / Q000633:toxicity; D013329:Structure-Activity Relationship
chemical_list: D012276:Ricin