scholarly journals Recognition of individual Escherichia coli transfer ribonucleic acids by 1-adenine-specific methyltransferase from rat liver

1978 ◽  
Vol 169 (1) ◽  
pp. 247-249 ◽  
Author(s):  
J Kraus
Keyword(s):  
Escherichia Coli ◽  
Rat Liver ◽  
Ribonucleic Acids ◽  
Trna Species ◽  
Trna Methyltransferase

Purified 1-adenine-specific tRNA methyltransferase from rat liver preferentially methylated Escherichia coli tRNA species containing the target adenylate residue in a G-T-psi-C-G-A-A-U-C sequence. The results of methylation of various tRNA species are discussed.

How Optimized Is the Translational Machinery in Escherichia coli, Salmonella typhimurium and Saccharomyces cerevisiae?

Genetics ◽  
1998 ◽  
Vol 149 (1) ◽  
pp. 37-44 ◽  
Author(s):  
Xuhua Xia
Keyword(s):  
Escherichia Coli ◽  
Saccharomyces Cerevisiae ◽  
Amino Acid ◽  
Salmonella Typhimurium ◽  
Codon Usage ◽  
Translational Efficiency ◽  
Square Root ◽  
Translational Machinery ◽  
Mutual Adaptation ◽  
Trna Species

Abstract The optimization of the translational machinery in cells requires the mutual adaptation of codon usage and tRNA concentration, and the adaptation of tRNA concentration to amino acid usage. Two predictions were derived based on a simple deterministic model of translation which assumes that elongation of the peptide chain is rate-limiting. The highest translational efficiency is achieved when the codon recognized by the most abundant tRNA reaches the maximum frequency. For each codon family, the tRNA concentration is optimally adapted to codon usage when the concentration of different tRNA species matches the square-root of the frequency of their corresponding synonymous codons. When tRNA concentration and codon usage are well adapted to each other, the optimal content of all tRNA species carrying the same amino acid should match the square-root of the frequency of the amino acid. These predictions are examined against empirical data from Escherichia coli, Salmonella typhimurium, and Saccharomyces cerevisiae.

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