title: Identification of lethal mutations in Escherichia coli genes encoding enzymes of the methylerythritol phosphate pathway.
abstract: The recently elucidated methylerythritol phosphate (MEP) pathway for isoprenoid biosynthesis is essential in eubacteria (including Escherichia coli), the malaria parasite, and plants, but is absent in animals. Therefore, the pathway enzymes are promising targets for the development of novel herbicides and antimicrobials that are potentially innocuous for humans. For an effective drug design, it is important to identify the residues required to preserve the structure and activity of the MEP pathway enzymes. Here, we report a genetic approach to identify such residues in E. coli. A strain harboring a synthetic operon that allows the production of isoprenoids through a MEP-independent pathway was used to screen for the otherwise lethal loss-of-function point mutations in the MEP pathway genes generated by ethylmethane sulfonate (EMS) mutagenesis. Besides confirming the role of residues involved in catalysis, our results define regions within several of the proteins with a potential key role for enzyme function.
authors.affiliation: Departament de Bioquímica i Biologia Molecular, Facultat de Química, Universitat de Barcelona, Spain.
authors.forename: Susanna
authors.initials: S
authors.lastname: Sauret-Güeto
authors.forename: Ana
authors.initials: A
authors.lastname: Ramos-Valdivia
authors.forename: Ester
authors.initials: E
authors.lastname: Ibáñez
authors.forename: Albert
authors.initials: A
authors.lastname: Boronat
authors.forename: Manuel
authors.initials: M
authors.lastname: Rodríguez-Concepción
mesh_terms: D000818:Animals; D004896:Erythritol / Q000737:chemistry / Q000378:metabolism*; D004926:Escherichia coli / Q000201:enzymology* / Q000235:genetics*; D029968:Escherichia coli Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D005798:Genes, Bacterial; D006801:Humans; D015394:Molecular Structure; D009154:Mutation; D010710:Phosphates / Q000737:chemistry / Q000378:metabolism
chemical_list: D029968:Escherichia coli Proteins; D010710:Phosphates; D004896:Erythritol