The ABC of ECF transporters. Discovery and initial characterization of ECF-type ATP-binding cassette (ABC) importers

PhD ceremony: Ms. J. ter Beek, 16.15 uur, Academiegebouw, Broerstraat 5, Groningen

Dissertation: The ABC of ECF transporters. Discovery and initial characterization of ECF-type ATP-binding cassette (ABC) importers

Promotor(s): prof. D.J. Slotboom, prof. B. Poolman

Faculty: Mathematics and Natural Sciences

Jozy ter Beek has discovered and characterized a new class of transporters. All living creatures are built up from cells. All cells are surrounded by a membrane that protects the inside of the cell from the outside. To survive, every cell has to take up (growth-)substances from its surroundings and excrete other (waste-)substances. To accomplish this many transport-proteins are present in the membrane.

The new class of transporters Ter Beek has discovered and characterized is part of a large group of transporters that uses the energy from adenosine triphosphate to pump substances across the cell membrane. Transporters of this group always consist of two proteins in the membrane and two proteins on the inside of the cell that work together. The new class of transporters only exists in bacteria and is important for the import of vitamins. The difference between the newly discovered class and the two other known classes of importers is that they do not use an additional protein at the outside of the cell to bind the substance that has to be transported. Instead, one of the proteins in the membrane is specialized to bind the substance. The other thing that makes these transporters stand out is that the protein that binds the substance can be exchanged by another protein that binds another substance. In this way a variety of substances can be transported.

Since these transporters only exist in bacteria and are used to transport various important substances, information on these transporters can in the future be used for the design of antibiotics.