Catalyzes the specific attachment of an amino acid to its cognate tRNA in a 2 step reaction: the amino acid (AA) is first activated by ATP to form AA-AMP and then transferred to the acceptor end of the tRNA . Plays a role in the synthesis of ribosomal RNA in the nucleolus .
Subcellular locations: Cytoplasm, Cytosol, Nucleus, Nucleolus
Localizes to the nucleolus in proliferative cells but disappears in quiescent cells.