Traditional medicines as a mechanism for driving research innovation in Africa.

The outcomes from recent high profile deliberations concerning African health research and economic development all point towards the need for a mechanism to support health innovation on the continent. The mission of the African Network for Drugs and Diagnostics Innovation (ANDI), is to promote and sustain African-led health product innovation to address African public health needs through the assembly of research networks, and building of capacity to support human and economic development. ANDI is widely viewed as the vehicle to implementing some of these recommendations.

EU-funded malaria research under the 6th and 7th Framework Programmes for research and technological development.

While malaria research has traditionally been strong in Europe, targeted and sustained support for cooperative malaria research at EU level, namely through the EU's 6th and 7th Framework Programmes for research and technological development, FP6 (2002-2006) and FP7 (2007-2013), has boosted both impact and visibility of European malaria research. Most of the European malaria research community is now organized under a number of comprehensive and complementary research networks and projects, assembled around four key areas: (1) fundamental research on the malaria parasite and the disease, (2) development of new malaria drugs, (3) research and development of a malaria vaccine, and (4) research to control the malaria-transmitting mosquito vector. Considerable efforts were undertaken to ensure adequate participation of research groups from disease-endemic countries, in particular from Africa, with the long-term aim to strengthen cooperative links and research capacities in these countries.

The essential HupB and HupN proteins of Pseudomonas putida provide redundant and nonspecific DNA-bending functions.

A protein mixture containing two major components able to catalyze a beta-recombination reaction requiring nonspecific DNA bending was obtained by fractionation of a Pseudomonas putida extract. N-terminal sequence analysis and genomic data base searches identified the major component as an analogue of HupB of Pseudomonas aeruginosa and Escherichia coli, encoding one HU protein variant. The minor component of the fraction, termed HupN, was divergent enough from HupB to predict a separate DNA-bending competence.

Activation and repression of transcription at the double tandem divergent promoters for the xylR and xylS genes of the TOL plasmid of Pseudomonas putida.

The xylR and xylS genes are divergent and control transcription of the TOL plasmid catabolic pathways for toluene metabolism. Four promoters are found in the 300-bp intergenic region: Pr1 and Pr2 are constitutive sigma70-dependent tandem promoters that drive expression of xylR, while expression of the xylS gene is driven from Ps2, a constitutive sigma70-dependent promoter, and by the regulatable sigma54 class Ps1 promoter. In Ps1 the XylR targets (upstream activator sequences [UASs]) overlap the Pr promoters, and two sites for integration host factor (IHF) binding are located at the region from positions -2 to -30 (-2/-30 region) and the -137/-156 region, the latter overlapping the Pr promoters.

Structure and function of the Pseudomonas putida integration host factor.

Integration host factor (IHF) is a DNA-binding and -bending protein that has been found in a number of gram-negative bacteria. Here we describe the cloning, sequencing, and functional analysis of the genes coding for the two subunits of IHF from Pseudomonas putida. Both the ihfA and ihfB genes of P.

sigma54-dependent transcription of the Pseudomonas putida xylS operon is influenced by the IIANtr protein of the phosphotransferase system in Escherichia coli.

IIANtr, encoded within the rpoN operons of many Gram-negative bacteria, is a homologue of a class of phosphoryl transfer proteins of the phosphoenolpyruvate: sugar phosphotransferase system. We have used a xylS operon-lacZ fusion from the TOL plasmid of Pseudomonas putida to show that IIANtr influences sigma 54-dependent transcription when the xylS operon is expressed in Escherichia coli. Loss of IIANtr influences, but does not abolish cyclic AMP-independent carbon catabolite repression.

Involvement of IHF protein in expression of the Ps promoter of the Pseudomonas putida TOL plasmid.

Regulation of the xyl gene operons of the Pseudomonas putida TOL plasmid is mediated by the products of the downstream clustered and divergently oriented xylR and xylS regulatory genes. The xylR-xylS intergenic region contains the xylR and xylS promoters Pr and Ps, respectively. A binding site for the XylR activator protein is located upstream of Ps and overlapping Pr.

Transcriptional induction kinetics from the promoters of the catabolic pathways of TOL plasmid pWW0 of Pseudomonas putida for metabolism of aromatics.

We determined, under several growth conditions, the kinetics of mRNA synthesis from the four Pseudomonas putida pWW0 plasmid promoters involved in degradation of xylenes and methylbenzyl alcohols via toluates. Transcription by XylS of the meta-cleavage pathway operon promoter (Pm) for the metabolism of alkylbenzoates was stimulated immediately after the addition of an effector, both in Luria-Bertani (LB) medium and in minimal medium. Activation of the sigma 54-dependent upper-pathway operon promoter (Pu) and the xylS gene promoter (Ps) by effector-activated XylR was dependent on the growth medium used: on minimal medium, activation of transcription from Pu and Ps occurred immediately after the addition of a XylR effector; in contrast, activation appeared only after several hours when cells were growing on LB medium.

Carbon source-dependent inhibition of xyl operon expression of the Pseudomonas putida TOL plasmid.

TOL plasmid-encoded degradation of benzyl alcohol by Pseudomonas putida is inhibited by glucose and other compounds related to the main carbohydrate metabolism in Pseudomonas species. We report here that this effect is exerted at the level of expression of the xyl catabolic operons, and two xyl promoters, Pu and Ps, were identified as the primary targets of this inhibition. xyl promoter activation was also inhibited by glucose in the heterologous Escherichia coli system, apparently not however by the classical mechanism of enteric catabolite repression.

Upstream binding sequences of the XylR activator protein and integration host factor in the xylS gene promoter region of the Pseudomonas TOL plasmid.

The xylR and xylS genes, which encode the positive regulators of the TOL plasmid catabolic pathways, are adjacent genes on the TOL plasmid and are transcribed from divergent promoters. Transcription from the xylS gene promoter, Ps, is positively regulated by effector-activated XylR protein and requires the specific RNA polymerase sigma 54 subunit (RpoN). Deletions and point mutations in the Ps upstream region localized the site of XylR interaction to the region between -133 bp and -207 bp (with respect to the transcriptional start of the xylS messenger), which contains an inverted sequence repeat largely homologous to the motif recognised by XylR in the XylR-regulated 'upper' catabolic pathway promoter, Pu.

Promoter-upstream activator sequences are required for expression of the xylS gene and upper-pathway operon on the Pseudomonas TOL plasmid.

Stimulation of transcription from the Pseudomonas TOL plasmid xylS gene promoter (Ps) and the upper-pathway operon promoter (Pu) is dependent on the positive regulator protein XylR activated by an effector molecule such as 3-cholorotoluene, and on RpoN, an RNA polymerase sigma factor. Mutational analysis of the Ps and Pu promoters showed that upstream activator sequences located between -110 and -218bp upstream of the main transcription initiation point are required for regulated expression from these promoters. A search for homologous nucleotide sequences in the -110 to -218bp region in Pu and Ps revealed conserved sequences that may act as putative recognition sequences for the XylR protein.

The Klebsiella pneumoniae PII protein (glnB gene product) is not absolutely required for nitrogen regulation and is not involved in NifL-mediated nif gene regulation.

The role of the Klebsiella pneumoniae PII protein (encoded by glnB) in nitrogen regulation has been studied using two classes of glnB mutants. In Class I mutants PII appears not to be uridylylated in nitrogen-limiting conditions and in Class II mutants PII is not synthesised. The effects of these mutations on expression from nitrogen-regulated promoters indicate that PII is not absolutely required for nitrogen control.

Identification of the Klebsiella pneumoniae glnB gene: nucleotide sequence of wild-type and mutant alleles.

The glnB gene of Klebsiella pneumoniae, which encodes the nitrogen regulation protein PII, has been cloned and sequenced. The gene encodes a 12429 dalton polypeptide and is highly homologous to the Escherichia coli glnB gene. The sequences of a glnB mutation which causes glutamine auxotrophy and of a Tn5 induced Gln+ suppressor of this mutation were also determined.