▁Lig ands ▁identified ▁would ▁be ▁expected ▁to ▁be ▁broad - spect rum ▁Gram - negative ▁in hib itors ▁in ▁experimental ▁ass ays ▁since ▁pe pt id og ly can ▁synth esis ▁is ▁exclusive ▁to ▁b acter ia . ▁ ▁Struct ural ▁and ▁mole cular ▁dock ing ▁studies ▁revealed ▁candidate ▁lig ands ▁for ▁mur C ▁and ▁mur E ▁lig ases . ▁ ▁Ident ifying ▁gen es ▁in ▁bi ological ▁path way ▁▁ ▁Th irty ▁years ▁after ▁the ▁post trans lation ally ▁modified ▁ ▁hist id ine ▁derivative ▁di ph th am ide ▁was ▁determined , ▁chem ogen om ics ▁was ▁used ▁to ▁discover ▁the ▁en zym e ▁responsible ▁for ▁the ▁final ▁step ▁in ▁its ▁synth esis . ▁ ▁D ip th am ide ▁is ▁a ▁post trans lation ally ▁modified ▁hist id ine ▁resid ue ▁found ▁on ▁the ▁translation ▁el ong ation ▁factor ▁ 2 ▁( e EF - 2 ). ▁▁ ▁The ▁first ▁two ▁steps ▁of ▁the ▁b ios yn thesis ▁path way ▁leading ▁to ▁dip th ine ▁have ▁been ▁known , ▁but ▁the ▁en zym e ▁responsible ▁for ▁the ▁amid ation ▁of ▁dip th ine ▁to ▁di ph th am ide ▁remained ▁a ▁mystery . ▁ ▁The ▁research ers ▁capital ized ▁on ▁Sac char omy ces ▁c ere vis iae ▁c of it ness ▁data . ▁C of it ness ▁data ▁is ▁data ▁representing ▁the ▁similarity ▁of ▁growth ▁fit ness ▁under ▁various ▁conditions ▁between ▁any ▁two ▁different ▁delet ion ▁stra ins . ▁Under ▁the ▁assumption ▁that ▁stra ins ▁lack ing ▁the ▁di