Dependence of depurination of oligoribonucleotides by ricin A-chain on divalent cations and chelating agents.
Ricin A-chain is a cytotoxic RNA N-glycosidase that inactivates eukaryotic ribosomes by depurinating the adenosine at position 4324 in 28S rRNA. The enzyme retains its specificity when a synthetic oligoribonucleotide (a 35-mer) that mimics the structure at the site of action is the substrate. However, covalent modification by ricin A-chain of the oligoribonucleotide but not of ribosomes, depends on the simultaneous presence of a divalent cation and a chelating agent.
Glück
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Department of Biochemistry and Molecular Biology, University of Chicago, IL 60637, USA.
Wool
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D001483:Base Sequence; D002614:Chelating Agents / Q000737:chemistry / Q000378:metabolism; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D009843:Oligoribonucleotides / Q000737:chemistry / Q000378:metabolism*; D012335:RNA, Ribosomal / Q000378:metabolism*; D012276:Ricin / Q000378:metabolism*
D002614:Chelating Agents; D009843:Oligoribonucleotides; D012335:RNA, Ribosomal; D012276:Ricin