Prof. Dr. Jan Pieter Abrahams
Basel University, Biozentrum


Cryo-EM of LonP1: a dynamic molecular machine


We determined structures of the full-length, wild type LONP1 mitochondrial unfoldase / protease in ten different conformational states. Our data indicate how LonP1 recognizes, binds, and translocates substrate protein, and how sequential ATP hydrolysis by each subunit control a sixfold rotational binding change mechanism. Rocking motions of the flexible N-domain assembly may assist thermal unfolding of the substrate protein, suggesting LonP1 is a Brownian ratchet with ATP hydrolysis preventing translocation reversal.


After graduating at Leiden University, I worked at the LMB in Cambridge - first as postdoc then as staff scientist (1990-1997) - and as professor at Leiden University (1997-2015). In 2015, I moved to Basel, to start a research group at the Biozentrum and lead the Laboratory of Biomolecular Research at the Paul Scherer Institute (PSI), where I also established the new Laboratory of Nanoscale Biology in 2018. I use high-energy electron diffraction and microscopy for high-resolution structure determination. In 2020, I stepped back as lab head to focus on my research. I am developing methods for measuring data of biological crystals and single molecules in diffraction, rather than imaging (like in transmission electron microscopy), because I observed that directly measuring dispersed electron diffraction data of biological samples, boosts the signal-to-noise by several orders of magnitude, compared to conventional transmission electron microscopy. The observation can be explained from first principles and does not depend on crystallinity of the sample.