the role of aminoacyl-trna synthetases in the in vivo synthesis of adenylylated bis ( 5'-nucleosidyl ) tetraphosphates ( ap4n ) was studied by measuring the concentration of these nucleotides in escherichia coli cells overproducing lysyl- , methionyl- phenylalanyl- , or valyl-trna synthetase .
C0002529
aminoacyl-trna synthetases
C0042301
valyl-trna synthetase