Periodic Reporting for period 2 - MycoRailway (Discovery and molecular investigation of mycobacterial transporters responsible for iron acquisition)
Reporting period: 2019-10-01 to 2021-03-31
Access to iron represents an Achilles heel of M. tuberculosis and basic research that is conducted in this project to understand iron acquisition at the molecular likely will help to generate new generations of urgently needed drugs against this devastating pathogen.
The aim of objective 2 is the identification of novel transporter proteins involved in siderophore shuttling based on Tn-Seq analysis of Mycobacterium smegmatis. In the meantime, two other groups have published similar Tn-Seq studies as the one planned by us. As the main aim of objective 2 was to characterize novel siderophore shuttling proteins at the biochemical and structural level, we now build on the published studies to investigate interesting candidate proteins.
The aim of objective 3 is to engineer human siderocalin in order to bind mycobacterial siderophores with high affinity. This third aim will be tackled in the second half of the project.
Despite the fact that M. tuberculosis is one of the most extensively studied organisms, its complex cell wall as well as technical hurdles to purify and characterize mycobacterial membrane proteins has so far impeded the molecular investigation of siderophore transport. On the other hand, a number of excellent pioneering studies have shed light on genetic and functional aspects of mycobactin-mediated iron acquisition, upon which experimental work of this proposal builds on. The project will deliver unprecedented insights into proteins responsible for siderophore transport across the two mycobacterial membranes. Further, we will engineer binding proteins to interfere with iron acquisition. Hence, the project will shed light on molecular mechanisms of mycobacterial membrane transport, which is a terra incognita and awaits fascinating novel discoveries. Thereby, our research facilitates the development of novel cures to treat globally emerging multidrug resistant strains of M. tuberculosis.