The answer is an aminoacyl-tRNA synthetase.
The aminoacyl-tRNA synthetase is an enzyme responsible for the attachment of an amino acid to tRNA. First, it binds the ATP and the amino acid which results in aminoacyl-AMP and inorganic pyrophosphate. Aminoacyl-AMP binds the appropriate tRNA molecule. The aminoacyl group dissociates from the complex with AMP and binds the tRNA molecule creating aminoacyl-tRNA.
