title: The role of tyrosine residues in the RNA N-glycosidase activity of cinnamomin A-chain.
abstract: Cinnamomin is a type II ribosome-inactivating protein (RIP) and its A-chain (CTA) is a RNA N-glycosidase. It is observed that modification of tyrosine residues by N-acetylimidazole (N-AI) causes almost complete loss of CTA activity. Adenine partially protects tyrosine residues from modification by N-AI. It is proposed that tyrosine residues are involved in the active site of CTA and they are crucial in recognition and binding of ribosomal RNA. Tryptophan residues of CTA are also studied by NBS modification.
authors.affiliation: State Key Laboratory of Molecular Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, The Chinese Academy of Science, 320 Yue-yang Road, Shanghai 200031, China.
authors.forename: Hong
authors.initials: H
authors.lastname: Xu
authors.forename: Wang-Yi
authors.initials: WY
authors.lastname: Liu
mesh_terms: D000225:Adenine / Q000737:chemistry / Q000378:metabolism; D020418:Algal Proteins; D001665:Binding Sites; D002474:Cell-Free System; D027424:Cinnamomum; D004789:Enzyme Activation; D007093:Imidazoles / Q000737:chemistry; D009699:N-Glycosyl Hydrolases / Q000737:chemistry / Q000378:metabolism*; D021122:Protein Subunits / Q000737:chemistry; D011506:Proteins / Q000737:chemistry / Q000378:metabolism*; D012335:RNA, Ribosomal / Q000737:chemistry / Q000378:metabolism; D011994:Recombinant Proteins / Q000737:chemistry; D054788:Ribosome Inactivating Proteins; D054790:Ribosome Inactivating Proteins, Type 2; D013050:Spectrometry, Fluorescence; D014364:Tryptophan / Q000737:chemistry / Q000378:metabolism; D014443:Tyrosine / Q000737:chemistry / Q000378:metabolism*
chemical_list: D020418:Algal Proteins; D007093:Imidazoles; D021122:Protein Subunits; D011506:Proteins; D012335:RNA, Ribosomal; D011994:Recombinant Proteins; D054790:Ribosome Inactivating Proteins, Type 2; C061930:cinnamomin, Phytophthora cinnamomi; D014443:Tyrosine; D014364:Tryptophan; D009699:N-Glycosyl Hydrolases; D054788:Ribosome Inactivating Proteins; D000225:Adenine; C012160:N-acetylimidazole