Flashing the light: XFEL on Cobalt/Nickel transporters


Cobalt and Nickel are essential microelements for the vast number of bacterial species, and many pathogens rely on the Co/Ni uptake systems for their pathogenicity and survival. At the same time, elevated levels of these metals within the cell are toxic, and therefore tight regulation of Co/Ni homeostasis is essential for viability. Not surprisingly, a specific set of membrane proteins has evolved to fulfill the function of Co/Ni import/export to/from the cell and its compartments. Up to date, only limited structural and mechanistic information is available for these transporters. In particular, it is not clear how (strict) substrate selectivity is achieved, especially the discrimination among similar ions (Ni2+, Co2+, Zn2+, Mn2+, Mg2+, etc.) via a selectivity filter. Here I propose to study the structure, selectivity and transport mechanism of members of the CorA family, which have developed different selectivities for divalent cations within the same structural scaffold, and two Co/Ni-specific ATP-driven transporters as virtually no structural information is available on how these transporters perform their functions.
I propose to investigate these proteins with both conventional X-ray crystallography and the novel and rapidly developing technique of Serial Femtosecond Crystallography with X-Ray Free Electron Laser (XFEL). This technique offers unprecedented new possibilities for the study of membrane proteins in particular, because it is uniquely compatible with lipidic cubic phase crystallization and allows studies with the very small crystals at nanoscale. Furthermore, it resolves the long-standing issue of the radiation damage because the data is collected before the damage occurs.
This proposal brings together state-of-the art methodology with important basic biochemical questions. The structural models obtained during this study will serve as the basis for the understanding of Co/Ni homeostasis and may serve as the starting point for the design of new antibiotics, as all of selected targets are found in pathogenic bacteria.


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Dr. A.I. Guskov

Verbonden aan

Rijksuniversiteit Groningen, Faculty of Science and Engineering (FSE), Biochemie


Dr. A.I. Guskov, M.V. Guskova MSc, A.R. Stetsenko MSc


01/07/2015 tot 30/06/2020