Perspectives and Insights into the Competition for Aminoacyl-tRNAs between the Translational Machinery and for tRNA Dependent Non-Ribosomal Peptide Bond Formation

Life

Angela W. S. Fung¹  Roshani Payoe¹  Richard P. Fahlman¹  Lluís Ribas de Pouplana² 

[1]Department of Biochemistry, Faculty of Medicine & Dentistry, University of Alberta, 474-MSB Edmonton, AB T6G 2H7, Canada

[2]

[3]Department of Biochemistry, Faculty of Medicine & Dentistry, University of Alberta, 474-MSB Edmonton, AB T6G 2H7, Canada

关键词: tRNA;    aminoacyl-tRNA;    L/F-transferase;    stringent response;    EF-Tu;    N-end rule;    (p)ppGpp;   

DOI  :  10.3390/life6010002

来源: mdpi

【 摘 要 】

Aminoacyl-tRNA protein transferases catalyze the transfer of amino acids from aminoacyl-tRNAs to polypeptide substrates. Different forms of these enzymes are found in the different kingdoms of life and have been identified to be central to a wide variety of cellular processes. L/F-transferase is the sole member of this class of enzyme found in Escherichia coli and catalyzes the transfer of leucine to the N-termini of proteins which result in the targeted degradation of the modified protein. Recent investigations on the tRNA specificity of L/F-transferase have revealed the unique recognition nucleotides for a preferred Leu-tRNA^Leu isoacceptor substrate. In addition to discussing this tRNA selectivity by L/F-transferase, we present and discuss a hypothesis and its implications regarding the apparent competition for this aminoacyl-tRNA between L/F-transferase and the translational machinery. Our discussion reveals a hypothetical involvement of the bacterial stringent response that occurs upon amino acid limitation as a potential cellular event that may reduce this competition and provide the opportunity for L/F-transferase to readily increase its access to the pool of aminoacylated tRNA substrates.

【 授权许可】

CC BY   
© 2015 by the authors; licensee MDPI, Basel, Switzerland.