ATP + L-phenylalanine + tRNA(Phe) = AMP + diphosphate + H(+) + L-phenylalanyl-tRNA(Phe) Binds 2 magnesium ions per tetramer. Tetramer of two alpha and two beta subunits. Belongs to the phenylalanyl-tRNA synthetase beta subunit family. Type 1 subfamily. Lacks the conserved glutamate residue in position 469 that binds magnesium; it is replaced by a serine residue.