The identification of five genetic loci of Francisella novicida associated with intracellular growth.
Five transposon mutants of Francisella novicida were isolated that are compromised in their ability to grow in mouse macrophages in vitro. Sequence analysis of the DNA flanking the transposon insertions identified the genes that were interrupted in these mutants. One of the inactivated loci corresponds to the Francisella tularensis gene that encodes a 23-kDa protein that is the most prominently induced protein following macrophage infection. Another insertion was localised to approximately 2 kb upstream of the gene encoding the 23-kDa protein. By analysis of the incomplete Francisella genome sequence it was surmised that these two insertions disrupt different portions of a putative operon that encodes four proteins, none of which have discernible functions. Three other interrupted loci associated with poor intramacrophage growth showed similarity at the deduced amino acid level to alanine racemase, the ClpB heat-shock protease, and the purine biosynthetic enzyme, glutamine phosphoribosylpyrophosphate amidotransferases.
Gray
Catherine G
CG
Department of Biochemistry and Microbiology, University of Victoria, P.O. Box 3055 STN CSC, Victoria, BC, Canada V8W 3P6.
Cowley
Siobhán C
SC
Cheung
Karen K M
KK
Nano
Francis E
FE
D000818:Animals; D004251:DNA Transposable Elements / Q000235:genetics*; D004269:DNA, Bacterial / Q000235:genetics; D005603:Francisella / Q000235:genetics* / Q000254:growth & development*; D066298:In Vitro Techniques; D008264:Macrophages / Q000382:microbiology*; D008322:Mammals; D051379:Mice; D016296:Mutagenesis
D004251:DNA Transposable Elements; D004269:DNA, Bacterial