Disruption of key NADH-binding pocket residues of the Mycobacterium tuberculosis InhA affects DD-CoA binding ability.

Tuberculosis (TB) is a global health problem that affects over 10 million people. There is an urgent need to develop novel antimicrobial therapies to combat TB. To achieve this, a thorough understanding of key validated drug targets is required. The enoyl reductase InhA, responsible for synthesis of essential mycolic acids in the mycobacterial cell wall, is the target for the frontline anti-TB drug isoniazid. To better understand the activity of this protein a series of mutants, targeted to the NADH co-factor binding pocket were created. Residues P193 and W222 comprise a series of hydrophobic residues surrounding the cofactor binding site and mutation of both residues negatively affect InhA function. Construction of an M155A mutant of InhA results in increased affinity for NADH and DD-CoA turnover but with a reduction in Vmax for DD-CoA, impairing overall activity. This suggests that NADH-binding geometry of InhA likely permits long-range interactions between residues in the NADH-binding pocket to facilitate substrate turnover in the DD-CoA binding region of the protein. Understanding the precise details of substrate binding and turnover in InhA and how this may affect protein-protein interactions may facilitate the development of improved inhibitors enabling the development of novel anti-TB drugs.

2nd Congress on applied synthetic biology in Europe (Málaga, Spain, November 2013).

The second meeting organised by the EFB on the advances of applied synthetic biology in Europe was held in Málaga, Spain in November 2013. The potential for the broad application of synthetic biology was reflected in the five sessions of this meeting: synthetic biology for healthcare applications, tools and technologies for synthetic biology, production of recombinant proteins, synthetic plant biology, and biofuels and other small molecules. Outcomes from the meeting were that synthetic biology offers methods for rapid development of new strains that will result in decreased production costs, sustainable chemical production and new medical applications. Additionally, it also introduced novel ways to produce sustainable energy and biofuels, to find new alternatives for bioremediation and resource recovery, and environmentally friendly foodstuff production. All the above-mentioned advances could enable biotechnology to solve some of the major problems of Society. However, while there are still limitations in terms of lacking tools, standardisation and suitable host organisms, this meeting has laid a foundation providing cutting-edge concepts and techniques to ultimately convert the potential of synthetic biology into practice.