title: Protoporphyrinogen oxidase inhibitor: an ideal target for herbicide discovery.
abstract: As the last common enzyme in the biosynthetic pathway leading to heme and chlorophyll, protoporphyrinogen oxidase (PPO; EC 1.3.3.4) is an ideal target for herbicide development. Currently, about 30 PPO inhibitors have been developed as agricultural herbicides. PPO inhibitors have displayed  environmentally benign, but advantageous characteristics, including low toxicity, low effective concentration, broad herbicidal spectrum (active against both monocotyledon and dicotyledon weeds), quick onset of action, and long lasting effect. Over the last several years, great achievements  have been made in revealing the structural biology of PPO. Five PPO crystal structures, four isolated in enzyme-inhibitor complexes and one in the native form, have been determined, including those from Nicotiana tabacum, Myxococcus Xanthus, Bacillus subtilis, and human. Although PPO  inhibitors have been developed for over forty years, we continue to uncover exciting future prospects for novel PPO-inhibiting herbicides. In this review, we have summarized the structures of PPOs from plants, human, and bacteria; the interactions between PPOs and inhibitors; the quantitative  structure-activity relationships of PPO inhibitors; and the molecular design of new PPO inhibitors.
authors.affiliation: College of Chemistry, Central China Normal University Key Laboratory of Pesticide & Chemical Biology of Ministry of Education Wuhan 430079, P. R. China.
authors.forename: Ge-Fei
authors.initials: GF
authors.lastname: Hao
authors.forename: Yang
authors.initials: Y
authors.lastname: Zuo
authors.forename: Sheng-Gang
authors.initials: SG
authors.lastname: Yang
authors.forename: Guang-Fu
authors.initials: GF
authors.lastname: Yang
mesh_terms: D004791:Enzyme Inhibitors / Q000494:pharmacology*; D006540:Herbicides / Q000737:chemistry*; D008958:Models, Molecular; D011487:Protein Conformation; D050768:Protoporphyrinogen Oxidase / Q000037:antagonists & inhibitors* / Q000737:chemistry; D021281:Quantitative Structure-Activity Relationship
chemical_list: D004791:Enzyme Inhibitors; D006540:Herbicides; D050768:Protoporphyrinogen Oxidase