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Modifications of 60 S ribosomal subunits induced by the ricin A chain
Author(s) -
Paleologue Anne,
Reboud Jean Paul,
Reboud Anne-Marie
Publication year - 1986
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/0014-5793(86)81052-3
Subject(s) - protein subunit , ricin , toxin , chemistry , nucleoprotein , nuclease , biochemistry , denaturation (fissile materials) , ribosomal rna , rna , microbiology and biotechnology , biology , dna , nuclear chemistry , gene
Incubation of 60 S ribosomal subunits with the ricin A chain reduced their stability during heat treatment. The toxin shifted the thermal denaturation curve of the subunits towards lower temperatures, in a similar way to that produced by the decrease in Mg 2+ concentration. A brief heating (3 min at 57°C), which did not affect control subunit activity, enhanced protein synthesis inhibition of the toxin‐treated subunits that released more 5 S RNA, in the form of nucleoprotein complex(es) with protein L5 and phosphoproteins P1P2 (RNP H ), than did heated control subunits [(1984) Eur. J. Biochem, 143, 303‐307]. No nuclease activity tested on 60 S subunits and purified 5 S and 5.8 S RNA was found associated with the toxin. The results suggest that the toxin induced a limited conformational change of the 60 S subunit, which destabilized the interaction between RNP H and the rest of the subunit.