title: The Mycobacterium tuberculosis shikimate pathway genes: evolutionary relationship between biosynthetic and catabolic 3-dehydroquinases.
abstract: The Mycobacterium tuberculosis shikimate pathway genes designated aroB and aroQ encoding 3-dehydroquinate synthase and 3-dehydroquinase, respectively were isolated by molecular cloning and their nucleotide sequences determined. The deduced dehydroquinate synthase amino acid sequence from M. tuberculosis showed high similarity to those of equivalent enzymes from prokaryotes and filamentous fungi. Surprisingly, the deduced M. tuberculosis 3-dehydroquinase amino acid sequence showed no similarity to other characterised prokaryotic biosynthetic 3-dehydroquinases (bDHQases). A high degree of similarity was observed, however, to the fungal catabolic 3-dehydroquinases (cDHQases) which are active in the quinic acid utilisation pathway and are isozymes of the fungal bDHQases. This finding indicates a common ancestral origin for genes encoding the catabolic dehydroquinases of fungi and the biosynthetic dehydroquinases present in some prokaryotes. Deletion of genes encoding shikimate pathway enzymes represents a possible approach to generation of rationally attenuated strains of M. tuberculosis for use as live vaccines.
authors.affiliation: MRC Tuberculosis and Related Infections Unit, Hammersmith Hospital, London, UK.
authors.forename: T
authors.initials: T
authors.lastname: Garbe
authors.forename: S
authors.initials: S
authors.lastname: Servos
authors.forename: A
authors.initials: A
authors.lastname: Hawkins
authors.forename: G
authors.initials: G
authors.lastname: Dimitriadis
authors.forename: D
authors.initials: D
authors.lastname: Young
authors.forename: G
authors.initials: G
authors.lastname: Dougan
authors.forename: I
authors.initials: I
authors.lastname: Charles
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D005075:Biological Evolution; D004587:Electrophoresis, Agar Gel; D004591:Electrophoresis, Polyacrylamide Gel; D004926:Escherichia coli / Q000235:genetics; D005798:Genes, Bacterial; D006836:Hydro-Lyases / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism*; D007527:Isoenzymes / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism; D008190:Lyases / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D009154:Mutation; D009169:Mycobacterium tuberculosis / Q000235:genetics; D019761:Phosphorus-Oxygen Lyases; D015183:Restriction Mapping; D012689:Sequence Homology, Nucleic Acid; D012765:Shikimic Acid / Q000378:metabolism*
chemical_list: D007527:Isoenzymes; D012765:Shikimic Acid; D008190:Lyases; D006836:Hydro-Lyases; C020000:3-dehydroquinate dehydratase; C020001:3-dehydroquinate synthetase; D019761:Phosphorus-Oxygen Lyases