Defence Science and Technology Laboratory

About: Defence Science and Technology Laboratory is a government organization based out in Salisbury, United Kingdom. It is known for research contribution in the topics: Burkholderia pseudomallei & Francisella tularensis. The organization has 926 authors who have published 1242 publications receiving 30091 citations. The organization is also known as: Dstl & [dstl].

Substrate recognition and mechanism revealed by ligand-bound polyphosphate kinase 2 structures.

Abstract: Inorganic polyphosphate is a ubiquitous, linear biopolymer built of up to thousands of phosphate residues that are linked by energy-rich phosphoanhydride bonds. Polyphosphate kinases of the family 2 (PPK2) use polyphosphate to catalyze the reversible phosphorylation of nucleotide phosphates and are highly relevant as targets for new pharmaceutical compounds and as biocatalysts for cofactor regeneration. PPK2s can be classified based on their preference for nucleoside mono- or diphosphates or both. The detailed mechanism of PPK2s and the molecular basis for their substrate preference is unclear, which is mainly due to the lack of high-resolution structures with substrates or substrate analogs. Here, we report the structural analysis and comparison of a class I PPK2 (ADP-phosphorylating) and a class III PPK2 (AMP- and ADP-phosphorylating), both complexed with polyphosphate and/or nucleotide substrates. Together with complementary biochemical analyses, these define the molecular basis of nucleotide specificity and are consistent with a Mg2+ catalyzed in-line phosphoryl transfer mechanism. This mechanistic insight will guide the development of PPK2 inhibitors as potential antibacterials or genetically modified PPK2s that phosphorylate alternative substrates.

Yersinia pseudotuberculosis mntH functions in intracellular manganese accumulation, which is essential for virulence and survival in cells expressing functional Nramp1

Abstract: Manganese has an important yet undefined role in the virulence of many bacterial pathogens. In this study we confirm that a null mutation in Yersinia pseudotuberculosis mntH reduces intracellular manganese accumulation. An mntH mutant was susceptible to killing by reactive oxygen species when grown under manganese-limited conditions. The mntH mutant was defective in survival and growth in macrophages expressing functional Nramp1, but in macrophages deficient in Nramp the bacteria were able to survive and replicate. In Galleria mellonella, the mntH mutant was attenuated. Taken together, these data suggest a role for manganese in Y. pseudotuberculosis during macrophage intracellular survival, protecting the bacteria from the antimicrobial products released during the respiratory burst.

Proteomic analysis of Bacillus subtilis strains engineered for improved production of heterologous proteins.

Abstract: The use of bacterial systems for recombinant protein production has advantages of simplicity, time and cost over competing systems However, widely used bacterial expression systems (eg Escherichia coli, Pseudomonas fluorescens) are not able to secrete soluble proteins directly into the culture medium This limits yields and increases downstream processing time and costs In contrast, Bacillus spp secrete native enzymes directly into the culture medium at grams-per-litre quantities, although the yields of some recombinant proteins are severely limited We have engineered the Bacillus subtilis genome to generate novel strains with precise deletions in the genes encoding ten extracytoplasmic proteases that affect recombinant protein secretion, which lack chromosomal antibiotic resistance genes The deletion sites and presence of single nucleotide polymorphisms were confirmed by sequencing The strains are stable and were used in industrial-scale fermenters for the production of the Bacillus anthracis vaccine protein, protective antigen, the productivity of which is extremely low in the unmodified strain We also show that the deletion of so-called quality control proteases appears to influence cell-wall synthesis, resulting in the induction of the cell-wall stress regulon that encodes another quality control protease