Biomaterial Database

Analysis of the steady-state mechanism of the aminoacylation of tRNAPhe by phenylalanyl-tRNA synthetase from yeast. 1978

R Thiebe

The steady-state mechanism of the aminoacylation of tRNAPhe by the corresponding synthetase from yeast has been investigated in detail by kinetic experiments. It was found that there are two alternative mechanisms: one favoured at low tRNA concentrations and the other at high tRNA concentrations. ATP and Phe are bound randomly to the enzyme. AMP is released immediately after the binding of ATP and Phe. Between the release of AMP and pyrophosphate (PPi) there is at least one additional step. Based on the experimental results a model of the steady-state mechanism is proposed. This model includes the sequence of addition of substrates to the enzyme and the release of products from the enzyme as well as the composition of the intermediate complexes with the enzyme. This model is in accordance with previous results based on different techniques. The results are explained by a "flip-flop" mechanism for all the substrates and products involved in the reaction.

UI	MeSH Term	Description	Entries
D007700	Kinetics	The rate dynamics in chemical or physical systems.
D010649	Phenylalanine	An essential aromatic amino acid that is a precursor of MELANIN; DOPAMINE; noradrenalin (NOREPINEPHRINE), and THYROXINE.	Endorphenyl,L-Phenylalanine,Phenylalanine, L-Isomer,L-Isomer Phenylalanine,Phenylalanine, L Isomer
D010652	Phenylalanine-tRNA Ligase	An enzyme that activates phenylalanine with its specific transfer RNA. EC 6.1.1.20.	Phenylalanyl T RNA Synthetase,Phe-tRNA Ligase,Phenylalanyl-tRNA Synthetase,Ligase, Phe-tRNA,Ligase, Phenylalanine-tRNA,Phe tRNA Ligase,Phenylalanine tRNA Ligase,Phenylalanyl tRNA Synthetase,Synthetase, Phenylalanyl-tRNA
D000604	Amino Acyl-tRNA Synthetases	A subclass of enzymes that aminoacylate AMINO ACID-SPECIFIC TRANSFER RNA with their corresponding AMINO ACIDS.	Amino Acyl T RNA Synthetases,Amino Acyl-tRNA Ligases,Aminoacyl Transfer RNA Synthetase,Aminoacyl-tRNA Synthetase,Transfer RNA Synthetase,tRNA Synthetase,Acyl-tRNA Ligases, Amino,Acyl-tRNA Synthetases, Amino,Amino Acyl tRNA Ligases,Amino Acyl tRNA Synthetases,Aminoacyl tRNA Synthetase,Ligases, Amino Acyl-tRNA,RNA Synthetase, Transfer,Synthetase, Aminoacyl-tRNA,Synthetase, Transfer RNA,Synthetase, tRNA,Synthetases, Amino Acyl-tRNA
D012343	RNA, Transfer	The small RNA molecules, 73-80 nucleotides long, that function during translation (TRANSLATION, GENETIC) to align AMINO ACIDS at the RIBOSOMES in a sequence determined by the mRNA (RNA, MESSENGER). There are about 30 different transfer RNAs. Each recognizes a specific CODON set on the mRNA through its own ANTICODON and as aminoacyl tRNAs (RNA, TRANSFER, AMINO ACYL), each carries a specific amino acid to the ribosome to add to the elongating peptide chains.	Suppressor Transfer RNA,Transfer RNA,tRNA,RNA, Transfer, Suppressor,Transfer RNA, Suppressor,RNA, Suppressor Transfer
D012441	Saccharomyces cerevisiae	A species of the genus SACCHAROMYCES, family Saccharomycetaceae, order Saccharomycetales, known as "baker's" or "brewer's" yeast. The dried form is used as a dietary supplement.	Baker's Yeast,Brewer's Yeast,Candida robusta,S. cerevisiae,Saccharomyces capensis,Saccharomyces italicus,Saccharomyces oviformis,Saccharomyces uvarum var. melibiosus,Yeast, Baker's,Yeast, Brewer's,Baker Yeast,S cerevisiae,Baker's Yeasts,Yeast, Baker