A mutation in the putative CRP binding site of the promoter of serovar Typhimurium enables growth with low orotate concentrations.

and use the inner membrane transporter DctA to import the pyrimidine biosynthetic pathway intermediate orotate from the environment. To study the regulation of expression, we used an serovar Typhimurium pyrimidine auxotroph to select a mutant that could grow in an otherwise nonpermissive culture medium containing glucose and a low concentration of orotate. Whole genome sequencing revealed a point mutation upstream of in the putative cyclic AMP receptor protein (CRP) binding site.

Human papillomavirus typing and viral gene expression analysis for the triage of women with abnormal results from papanicolaou test smears to colposcopy.

Context: A cascade of molecular tests for human papillomavirus (HPV), as a follow-up to Papanicolaou test screening, could eliminate unnecessary colposcopy. Tests based on detection of HPV E6 messenger RNA (mRNA) are already being used as screening tools, but there is a good biological rationale for expecting that an increase in the relative amounts of HPV E6 mRNA in cervical samples may better predict cancerous transformation.

Objective: To compare some of the available diagnostic methods and our novel method of relative quantification (RQ) of HPV gene expression for the effective triage of women with abnormal results from Papanicolaou tests to colposcopy.

The impact of the distribution of human papillomavirus types and associated high-risk lesions in a colposcopy population for monitoring vaccine efficacy.

Context: Impact studies of the new human papillomavirus (HPV) vaccines will be biased unless local baseline distribution studies are conducted. Vaccine cross protection for other important oncogenic HPV types and the emergence of potential genotype replacements require the knowledge of the prevaccine epidemiology of HPV.

Objective: To determine the prevaccine distribution of HPV types in Saskatchewan, using a subpopulation of women referred to a colposcopy clinic.

Mutations in yhiT enable utilization of exogenous pyrimidine intermediates in Salmonella enterica serovar Typhimurium.

Mutants capable of utilizing the pyrimidine biosynthetic intermediates carbamoylaspartate and dihydroorotate for growth were derived from pyrimidine auxotrophs of Salmonella enterica serovar Typhimurium LT2. The gain-of-function phenotypes both resulted from mutations in a single gene, yhiT, the third gene of a putative four-gene operon, yhiVUTS, for which there is no homologous region in Escherichia coli. Notably, when a mutant yhiT allele was transferred to a pyrimidine-requiring E.

Structure-function relationships of UMP kinases from pyrH mutants of Gram-negative bacteria.

Bacterial uridine monophosphate (UMP) kinases are essential enzymes encoded by pyrH genes, and conditional-lethal or other pyrH mutants were analysed with respect to structure-function relationships. A set of thermosensitive pyrH mutants from Escherichia coli was generated and studied, along with already described pyrH mutants from Salmonella enterica serovar Typhimurium. It is shown that Arg-11 and Gly-232 are key residues for thermodynamic stability of the enzyme, and that Asp-201 is important for both catalysis and allosteric regulation.

Regulation of expression of the 2-deoxy-D-ribose utilization regulon, deoQKPX, from Salmonella enterica serovar typhimurium.

Salmonella enterica, in contrast to Escherichia coli K12, can use 2-deoxy-D-ribose as the sole carbon source. The genetic determinants for this capacity in S. enterica serovar Typhimurium include four genes, of which three, deoK, deoP, and deoX, constitute an operon.