title: Sequencing of the Francisella tularensis strain Schu 4 genome reveals the shikimate and purine metabolic pathways, targets for the construction of a rationally attenuated auxotrophic vaccine.
abstract: Francisella tularensis is the etiological agent of tularemia, a serious disease in several Northern hemisphere countries. The organism has fastidious growth requirements and is very poorly understood at the genetic and molecular levels. Given the lack of data on this organism, we undertook the sample sequencing of its genome. A random library of DNA fragments from a highly virulent strain (Schu 4) of F. tularensis was constructed and the nucleotide sequences of 13,904 cloned fragments were determined and assembled into 353 contigs. A total of 1.83 Mb of nucleotide sequence was obtained that had a G+C content of 33.2%. Genes located on plasmids pOM1 and pNFL10, which had been previously isolated from low virulence strains of F. tularensis, were absent but all of the other known F. tularensis genes were represented in the assembled data. F. tularensis Schu4 was able to grow in the absence of aromatic amino acids and orthologues of genes which could encode enzymes in the shikimate pathway in other bacteria were identified in the assembled data. Genes that could encode all of the enzymes in the purine biosynthetic and most of the en- zymes in the purine salvage pathways were also identified. This data will be used to develop defined rationally attenuated mutants of F. tularensis, which could be used as replacements for the existing genetically undefined live vaccine strain.
authors.affiliation: National Defence Research Establishment, Umeå, Sweden.
authors.forename: J
authors.initials: J
authors.lastname: Karlsson
authors.forename: R G
authors.initials: RG
authors.lastname: Prior
authors.forename: K
authors.initials: K
authors.lastname: Williams
authors.forename: L
authors.initials: L
authors.lastname: Lindler
authors.forename: K A
authors.initials: KA
authors.lastname: Brown
authors.forename: N
authors.initials: N
authors.lastname: Chatwell
authors.forename: K
authors.initials: K
authors.lastname: Hjalmarsson
authors.forename: N
authors.initials: N
authors.lastname: Loman
authors.forename: K A
authors.initials: KA
authors.lastname: Mack
authors.forename: M
authors.initials: M
authors.lastname: Pallen
authors.forename: M
authors.initials: M
authors.lastname: Popek
authors.forename: G
authors.initials: G
authors.lastname: Sandström
authors.forename: A
authors.initials: A
authors.lastname: Sjöstedt
authors.forename: T
authors.initials: T
authors.lastname: Svensson
authors.forename: I
authors.initials: I
authors.lastname: Tamas
authors.forename: S G
authors.initials: SG
authors.lastname: Andersson
authors.forename: B W
authors.initials: BW
authors.lastname: Wren
authors.forename: P C
authors.initials: PC
authors.lastname: Oyston
authors.forename: R W
authors.initials: RW
authors.lastname: Titball
mesh_terms: D001428:Bacterial Vaccines; D005604:Francisella tularensis / Q000235:genetics*; D005798:Genes, Bacterial; D016680:Genome, Bacterial; D008954:Models, Biological; D011687:Purines / Q000378:metabolism*; D017422:Sequence Analysis, DNA; D012765:Shikimic Acid / Q000378:metabolism*; D014613:Vaccines, Attenuated
chemical_list: D001428:Bacterial Vaccines; D011687:Purines; D014613:Vaccines, Attenuated; D012765:Shikimic Acid