The external aldimine form of the Salmonella thypi wild-type tryptophan synthase in open conformation showing multiple side chain conformations for the residue beta Q114 and sodium ion at the metal coordination site. One of the beta-Q114 rotamer conformations allows a hydrogen bond to form with the PLP oxygen at the position 3 in the ring.
Hilario, E., Fan, L., Dunn, M.F., Mueller, L.J.To be published.