Release of polypeptide chain initiation factor IF-2 during initiation complex formation.

A H Lockwood; P Sarkar; U Maitra

doi:10.1073/pnas.69.12.3602

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Release of polypeptide chain initiation factor IF-2 during initiation complex formation.

A H Lockwood·P Sarkar·U Maitra

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Abstract

Polypeptide chain initiation factor IF-2 binds to 30S ribosomal subunits. This binding is enhanced by IF-1 and IF-3. During GTP-dependent formation of a 70S initiation complex, IF-2 is released from the ribosome. During 70S initiation complex formation dependent on the methylene analogue of GTP, GMPPCH(2)P, IF-2 is not released, but remains bound to the 70S ribosome. This result suggests that IF-2 release requires GTP hydrolysis. In agreement with this presumed requirement, IF-2 functions catalytically with GTP, but stoichiometrically with GMPPCH(2)P, in bringing about 70S initiation complex formation.

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Centrifugation, Density Gradient Escherichia coli Guanine Nucleotides Guanosine Triphosphate Hydrolysis Methionine Peptide Chain Initiation, Translational Peptide Initiation Factors Polynucleotides Protein Binding RNA, Transfer Ribosomes Tritium Journal Article

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A H Lockwood, P Sarkar, U Maitra. 1972. Release of polypeptide chain initiation factor IF-2 during initiation complex formation.. https://doi.org/10.1073/pnas.69.12.3602

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