RT Journal Article
SR Electronic
T1 Structure of the Large β-Chain Polyribosome of Rabbit Reticulocytes Rendered Isoleucine-Deficient by O-Methylthreonine
JF Molecular Pharmacology
JO Mol Pharmacol
FD American Society for Pharmacology and Experimental Therapeutics
SP 317
OP 322
VO 7
IS 3
A1 MICHAEL L. FREEDMAN
A1 MARCO RABINOVITZ
YR 1971
UL http://molpharm.aspetjournals.org/content/7/3/317.abstract
AB Incubation of rabbit reticulocytes with L-O-methylthreonine, an analogue of L-isoleucine, results in the formation of a unique, large β-chain polyribosome containing approximately 12 ribosomes. Two possible mechanisms for the formation of this polyribosome are considered: (a) the polyribosome may be formed by maximal packing of ribosomes on a β-chain mRNA strand proximal to the limiting isoleucine codon, on (b) there may be dimerization of lighter polyribosomes by an interaction of the blocked nascent β-chains. The nascent chains were removed from the ribosomes in intact cells by incubation with puromycin, and from the isolated ribosome-polyribosome component by incubation with Pronase. In both cases the large polyribosome remained after the nascent chains were removed, suggesting that it is formed by maximal packing of ribosomes on a β-chain mRNA strand.