Polypeptide chain initiation and stepwise elongation with Artemia ribosomes and factors.
Proc Natl Acad Sci U S A
; 69(9): 2451-5, 1972 Sep.
Article
en En
| MEDLINE
| ID: mdl-4560686
The supernatant initiation factor from Artemia salina embryos promotes, besides the AUG-dependent binding of fMet-tRNA(f), the poly(U)-dependent binding of N-acetylPhe-tRNA to 40S ribosomal subunits; the bound N-acylaminoacyl-tRNA reacts directly with puromycin upon addition of 60S subunits. Both the binding reaction and the synthesis of N-acylaminoacyl-puromycin occur in the absence of GTP or other ribonucleoside triphosphates. To a smaller extent, the factor also mediates the 40S ribosomal binding of Met-tRNA(f) and Phe-tRNA; in this case, the bound aminoacyl-tRNA is less reactive with puromycin. After the poly(U)- and supernatant factor-dependent binding of N-acetylPhe-tRNA to 40S subunits at low Mg(2+) concentration, binding of a second aminoacyl-tRNA (Phe-tRNA), with ensuing formation of the first peptide bond, is dependent upon the addition of the 60S subunit, elongation factor EF-1, and GTP. Further growth of the polypeptide chain requires translocation and is, therefore, dependent upon the addition of elongation factor EF-2. As with the Escherichia coli system, once requirements for translation of the third codon have been met, no further additions are necessary for elongation of a peptide chain.
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Biosíntesis de Péptidos
/
Ribosomas
Límite:
Animals
Idioma:
En
Revista:
Proc Natl Acad Sci U S A
Año:
1972
Tipo del documento:
Article
Pais de publicación:
Estados Unidos