The highly conserved core sequence of amino acid residues (LGGHSI) in the phosphopantetheinylation (activation) domain of the antibiotic synthetases and Lys2p. Abbreviations for organisms: PENCH, P. chrysogenum; EMEN, Emericella nidulans; CEPAC, Cephalosporium acremonium; NOCLA, Nocardia lactamdurans; 1BACB, Bacillus brevis; BACB, Bacillus brevis; PCHR, P. chrysogenum; SPOM, S. pombe; SCER, S. cerevisiae; CALB, C. albicans.