TY - JOUR
T1 - The mechanism of the aminoacylation of transfer ribonucleic acid The kinetics and stoichiometry of the lysis of aminoacyl-tRNA
AU - Jakubowski, Hieronim
AU - Pastuszyn, Andrzej
AU - Loftfield, Robert B.
N1 - Funding Information:
This research has been supported by American Cancer Society Grant NP 104.
PY - 1978/10/24
Y1 - 1978/10/24
N2 - It is often stated that the aminoacylation of transfer RNA proceeds in discrete steps: {A figure is presented} If this is a complete description of the reaction, the reverse overall formation of ATP should not be more rapid than the formation of Enz · (AA ∼ AMP). We show for four different amino acid:tRNA ligases that lysis of AA-tRNA (with PPi and AMP) to ATP is faster than lysis of AA-tRNA (with AMP only) to Enz · (AA ∼ AMP). This requires that the transition state proceeds from a quaternary complex of PPi, AMP, AA-tRNA and Enz. From the law of microscopic reversibility, this requires that in the forward reaction the AA-tRNA bond be formed before PPi leaves the enzyme complex. Therefore, the forward reaction passes through the quaternary complex Enz · ATP · AA · tRNA. (In view of recent evidence of the specific requirement of two cations, the complex is accurately described as senary.).
AB - It is often stated that the aminoacylation of transfer RNA proceeds in discrete steps: {A figure is presented} If this is a complete description of the reaction, the reverse overall formation of ATP should not be more rapid than the formation of Enz · (AA ∼ AMP). We show for four different amino acid:tRNA ligases that lysis of AA-tRNA (with PPi and AMP) to ATP is faster than lysis of AA-tRNA (with AMP only) to Enz · (AA ∼ AMP). This requires that the transition state proceeds from a quaternary complex of PPi, AMP, AA-tRNA and Enz. From the law of microscopic reversibility, this requires that in the forward reaction the AA-tRNA bond be formed before PPi leaves the enzyme complex. Therefore, the forward reaction passes through the quaternary complex Enz · ATP · AA · tRNA. (In view of recent evidence of the specific requirement of two cations, the complex is accurately described as senary.).
UR - https://www.scopus.com/pages/publications/0018189623
UR - https://www.scopus.com/pages/publications/0018189623#tab=citedBy
U2 - 10.1016/0005-2787(78)90142-9
DO - 10.1016/0005-2787(78)90142-9
M3 - Article
C2 - 214118
AN - SCOPUS:0018189623
SN - 0005-2787
VL - 520
SP - 568
EP - 576
JO - BBA Section Nucleic Acids And Protein Synthesis
JF - BBA Section Nucleic Acids And Protein Synthesis
IS - 3
ER -