title: Genetic evidence for the existence of two pathways for the biosynthesis of methionine in the Leptospira spp.
abstract: There are two major pathways for methionine biosynthesis: the enterobacterial type transsulfuration pathway and the sulfhydrylation pathway as previously identified in the spirochete Leptospira meyeri. Sequence analysis of the L. meyeri metYX locus allows the identification of a third gene, called metW, which encodes a protein exhibiting similarities with homologs in many organisms belonging to the alpha-, beta-, and gamma-subdivisions of proteobacteria. The metW, metX and metY genes of L. meyeri were disrupted by a resistance cassette by homologous recombination. While the L. meyeri metX mutant shows methionine auxotrophy, the metY mutant (as well as the metW and metYmetW mutants) conserves methionine prototrophy, suggesting the presence of additional route(s) which may bypass the direct sulfhydrylation pathway. In addition, a L. interrogans gene, called metZ, was found to complement an Escherichia coli metB mutant, further suggesting that the transsulfuration pathway is also present in Leptospira spp.
authors.affiliation: Unité de Bactériologie Moléculaire et Médicale, Institut Pasteur, 28 rue du docteur Roux, 75724 Paris Cedex 15, France. mpicard@pasteur.fr
authors.forename: Mathieu
authors.initials: M
authors.lastname: Picardeau
authors.forename: Hélène
authors.initials: H
authors.lastname: Bauby
authors.forename: Isabelle
authors.initials: I
authors.lastname: Saint Girons
mesh_terms: D000123:Acetyltransferases / Q000235:genetics / Q000378:metabolism; D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D019757:Carbon-Oxygen Lyases / Q000235:genetics / Q000378:metabolism; D003547:Cysteine Synthase; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D005816:Genetic Complementation Test; D007919:Leptospira / Q000235:genetics* / Q000378:metabolism*; D007921:Leptospira interrogans / Q000235:genetics; D008715:Methionine / Q000096:biosynthesis*; D008969:Molecular Sequence Data; D009097:Multienzyme Complexes; D016254:Mutagenesis, Insertional; D009876:Operon; D029701:Saccharomyces cerevisiae Proteins; D017385:Sequence Homology
chemical_list: D001426:Bacterial Proteins; D009097:Multienzyme Complexes; D029701:Saccharomyces cerevisiae Proteins; D008715:Methionine; D000123:Acetyltransferases; C021369:homoserine O-acetyltransferase; D003547:Cysteine Synthase; C103381:MET17 protein, S cerevisiae; C018725:O-acetylhomoserine (thiol)-lyase; D019757:Carbon-Oxygen Lyases