Crystal structures of Phd-Doc, HigA, and YeeU establish multiple evolutionary links between microbial growth-regulating toxin-antitoxin systems.
Arbing MA, Handelman SK, Kuzin AP, Verdon G, Wang C, Su M, Rothenbacher FP, Abashidze M, Liu M, Hurley JM, et al. Structure. 2010 Aug 11; 18(8):996-1010.