Requirement of an Escherichia coli 50 S Ribosomal Protein Component for Effective Interaction of the Ribosome with T and G Factors and with Guanosine Triphosphate

Hamel, Ernest; Koka, M.; Nakamoto, Takahisa

doi:10.1016/s0021-9258(19)45679-2

Cited by 365 publications

(67 citation statements)

References 47 publications

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“…At least one dimer constitutes the conspicuous morphological feature known as the L7/L12 stalk. L7/L12 can be selectively removed from and reconstituted back into the ribosome with concomitant loss and recovery of activity (Hamel et al, 1972;Tokimatsu et al, 1981). The amino acid sequence of E. coli L7/L12 revealed that each monomer possesses 120 residues with a molecular weight of 12.2 kDa (Terhorst et al, 1972).…”

mentioning

confidence: 99%

Rotational and Conformational Dynamics of Escherichia coli Ribosomal Protein L7/L12

et al. 1996

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Fluorescence methods were utilized to study dynamic aspects of the 24 kDa dimeric Escherichia coli ribosomal protein L7/L12. Oligonucleotide site-directed mutagenesis was used to introduce cysteine residues at specific locations along the peptide chain, in both the C-terminal and N-terminal domains, and various sulfhydryl reactive fluorescence probes (iodoacetamido) fluorescein, IAEDANS, pyrenemethyl iodoacetate) were attached to these residues. In addition to the full-length proteins, a hinge-deleted variant and variants corresponding to the C-terminal fragment and the N-terminal fragment were also studied. Both steady-state and time-resolved fluorescence measurements were carried out, and the results demonstrated that L7/L12 is not a rigid molecule. Specifically, the two C-terminal domains move freely with respect to one another and with respect to the dimeric N-terminal domain. Removal of the hinge region, however, significantly reduces the mobility of the C-terminal domains. The data also show that the rotational relaxation time monitored by the fluorescent probe-depends upon the probe's excited state lifetime. This observation is interpreted to indicate that a hierarchy of motions exists in the L7/L12 molecule including facile motions of the C-terminal domains and dimeric N-terminal domain, in addition to the overall tumbling of the protein. Probes attached to the N-terminal domain exhibit global rotational relaxation times consistent with the molecular mass of the dimeric N-terminal fragment. Upon reconstitution of labeled L7/L12 with ribosomal cores, however, the motion associated with the dimeric N-terminal domain is greatly diminished while the facile motion of the C-terminal domains is almost unchanged.

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confidence: 99%

Rotational and Conformational Dynamics of Escherichia coli Ribosomal Protein L7/L12

et al. 1996

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“…[14C]Phenylalanine of specific activity 513 Ci/mol was purchased from New England Nuclear Corp., and ATP, GTP, and pyruvate kinase were from General Biochemicals. Bovine pancreatic ribonuclease (RNase I), Type A, was purchased from Worthington Biochemicals, and T factor was prepared t' Dr. Ernest Hamel (Hamel et al. 1972).…”

Section: Methodsmentioning

confidence: 99%

Kinetic evidence for the obligatory formation of a 30S initiation complex in polyphenylalanine synthesis initiated with N-acetylphenylalanyl-tRNA

Blumberg¹,

Nakamoto²,

Goldberg³

1975

Biochemistry

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The problem of whether the initiation of bacterial protein synthesis involves the obligatory formation of a 30S initiation complex intermediate was examined in a model system with N-acetylphenylalanyl-tRNA as initiator 5RNA nad poly(uridylic acid) as mRNA. The time courses of the formation of the 30S and 70S initiation complex with Escherichia coli ribosomes were measured simultaneously by stopping the reaction with dextran sulfate and differentiating the N-acetylphenylalanyl-tRNA bound to 30S ribosomal subunits from that bound to 70S ribosomes with RNase I, which hydrolyzes N-acetylphenylalanyl-tRNA bound to 30S subunits but not that bound to 70S ribosomes. A maximum in the 30S complex concentration was observed within the first 10-15 sec of the reaction, whereas 70S complex formed formed more slowly with a slight initial time lag. When an analog computer was programmed with rate constants determined separately for the formation of the 30S initiation complex from preformed 30S complex, kinetic curves very similar to the empirical curves were obtained for the entire time course of the reaction. The results show clearly that formation of the 70S complex obeys the kinetic laws for consecutive reactions, and the 30S complex is, therefore, an obligatory intermediate in the initiation of polyphenylalanine synthesis in the model system.

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“…Elongation begins with the mRNA-independent binding of the aa-tRNA to the ribosome with EF-Tu and GTP [218]. Ternary complex interactions are mediated through EF-Tu and ribosomal protein L7/L12 [219]. The accuracy of the codon-anticodon interaction is assessed during two steps in the decoding centre.…”

Section: Decoding At the Ribosomementioning

confidence: 99%

Transfer RNAs: diversity in form and function

Berg

Brandl

2020

RNA Biology

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As the adaptor that decodes mRNA sequence into protein, the basic aspects of tRNA structure and function are central to all studies of biology. Yet the complexities of their properties and cellular roles go beyond the view of tRNAs as static participants in protein synthesis. Detailed analyses through more than 60 years of study have revealed tRNAs to be a fascinatingly diverse group of molecules in form and function, impacting cell biology, physiology, disease and synthetic biology. This review analyzes tRNA structure, biosynthesis and function, and includes topics that demonstrate their diversity and growing importance.

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Requirement of an Escherichia coli 50 S Ribosomal Protein Component for Effective Interaction of the Ribosome with T and G Factors and with Guanosine Triphosphate

Cited by 365 publications

References 47 publications

Rotational and Conformational Dynamics of Escherichia coli Ribosomal Protein L7/L12

Rotational and Conformational Dynamics of Escherichia coli Ribosomal Protein L7/L12

Kinetic evidence for the obligatory formation of a 30S initiation complex in polyphenylalanine synthesis initiated with N-acetylphenylalanyl-tRNA

Transfer RNAs: diversity in form and function

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