tRNA(also known as "transfer ribonucleic acid") to which its cognated amino acid is adhered. Their role is to deliver the amino acidto the ribosomewhere it will be incorporated into the polypeptidechain that is being produced.cite book | author = Berg J, Tymoczko JL, Stryer L | title = Biochemistry | publisher = W. H. Freeman | edition = 6th ed. | location = San Francisco | year = 2006 | isbn = 0716787245 ] A specific amino acid is added to each tRNA, which is crucial since it means that only that particular amino acid will be incorporated when the anticodon of that tRNA fits (can form a transient base pairwith) the next codon of the mRNAthat is being translated into protein.
The specific linkage of the correct amino acid to each tRNA is accomplished by
aminoacyl-tRNA synthetases. Due to the degeneracy of the genetic code, some of the different tRNAs have the same amino acid attached to them.
Aminoacyl-tRNA (also known as charged tRNA) is produced in two steps; amino acid activation and transfer. The first step is the adenylation of the amino acid, which forms aminoacyl-AMP:
Amino acid + ATP ↔ Aminoacyl-AMP + PPi
Then, the amino acid residue is transferred to the tRNA:
Aminoacyl-AMP + tRNA ↔ Aminoacyl-tRNA + AMP
The net reaction is
Amino acid + ATP + tRNA ↔ Aminoacyl-tRNA + AMP + PPi
The net reaction is only energetically favourable because the pyrophosphate is hydrolysed; that reaction is highly energetically favourable and drives the other reactions. All of these reactions take place inside the aminoacyl-tRNA synthetase specific for that tRNA.
Drugs that target aminoacyl-tRNA binding to ribosomal subunit
Certain drugs like
Erythromycinprevent the aminoacyl-tRNA from binding to the ribosomal subunitin prokaryotes.
Aminoacyl tRNA synthetase
Wikimedia Foundation. 2010.
Look at other dictionaries:
aminoacyl-tRNA — Generic term for those compounds in which amino acid s are esterfied through their COOH groups to the 3′ (or 2′ ) OH s of the terminal adenosine residues of transfer RNA s ( e.g., alanyl tRNA, glycyl tRNA); each compound involves one, or a small… … Medical dictionary
aminoacyl tRNA — Complex of an amino acid to its tRNA, formed by the action of aminoacyl tRNA synthetase. Requires ATP, which forms the linkage between the two molecules … Dictionary of molecular biology
aminoacyl-tRNA — aminoacil tRNR statusas T sritis chemija apibrėžtis Aminorūgšties ir tRNR esteris. atitikmenys: angl. aminoacyl tRNA rus. аминоацил тРНК … Chemijos terminų aiškinamasis žodynas
Aminoacyl-tRNA-Synthetase — Enzymklassifikation EC, Kategorie … Deutsch Wikipedia
Aminoacyl-tRNA Synthetase — Asp tRNA Synthetase Dimer aus zwei identischen Untereinheiten (blau und grün die beiden tRNAs sind rot) nach … Deutsch Wikipedia
aminoacyl-tRNA synthetase — n any of a class of amino acid specific enzymes that catalyze an ATP driven reaction producing an ester linkage between a carboxyl group of an amino acid and a hydroxyl group of its corresponding transfer RNA to form aminoacyl tRNA during the… … Medical dictionary
aminoacyl-tRNA synthetase — aminoacyl tRNA synthetase. См. активирующий фермент. (Источник: «Англо русский толковый словарь генетических терминов». Арефьев В.А., Лисовенко Л.А., Москва: Изд во ВНИРО, 1995 г.) … Молекулярная биология и генетика. Толковый словарь.
Aminoacyl-tRNA-Synthetase — ⇒ Translation … Deutsch wörterbuch der biologie
Aminoacyl tRNA synthetase — An aminoacyl tRNA synthetase (aaRS) is an enzyme that catalyzes the esterification of a specific amino acid or its precursor to one of all its compatible cognate tRNAs to form an aminoacyl tRNA. MechanismThe synthetase first binds ATP and the… … Wikipedia
Aminoacyl-tRNA hydrolase — In enzymology, an aminoacyl tRNA hydrolase (EC number|184.108.40.206) is an enzyme that catalyzes the chemical reaction:N Substituted aminoacyl tRNA + H2O ightleftharpoons N substituted amino acid + tRNAThus, the two substrates of this enzyme are N… … Wikipedia