Max Planck Institute of Biophysics

Dynamic network in the pores of the nuclear envelope blocks dangerous invaders

How SMC proteins pack the genetic material in the cell nucleus

Delta and Omicron mutants of the virus bind more tightly and longer to host cells than early Wuhan variants

Calcium ions tie cystine transporters for correct trafficking and function

12 Max Planck researchers win coveted ERC Advanced Grants

Talking with friends, enjoying a concert, talking on the phone on noisy streets – people with hearing problems are often unable to hear things that others can. Tobias Moser aims to make sound accessible to those with hearing disabilities in a whole new way through a new generation of hearing protheses. Known as optical cochlear implants, these devices serve as an example of therapies developed on the basis of fundamental research.

Chlamydomonas reinhardtii, a single-celled green alga, can’t see much at all with its eye composed solely of photosensitive rhodopsin molecules. Yet there is more to algal rhodopsin than one would expect. In recent years, it has triggered a revolution in neurobiology. Ernst Bamberg from the Max Planck Institute of Biophysics in Frankfurt helped make it famous. He is now researching these molecules and developing new variants for basic research and medical applications.

Single-particle electron cryo-microscopy (CryoEM) is ideal for determining the high-resolution structure membrane protein complexes that are too unstable or too dynamic for x-ray crystallography. Intact rotary ATPases have resisted crystallization for more than 40 years. However, central aspects of their mechanisms now have become clear thanks to the recent CryoEM based structures of intact, functional ATP synthases. The two best and most informative of these structures, the chloroplast ATP synthase and a mitochondrial ATP synthase dimer, have been shown by our department.

Flavin-based electron bifurcating (FBEB) enzyme complexes play a vital role in obligate anaerobic microorganisms for increasing the efficiency of their energy metabolism. They drive an endergonic reduction by an exergonic one via the same electron donor. The energy coupling is realized by a reduced flavin which transfers via energy splitting one strongly and one weakly reducing electron to two different substrates. How FBEB enzyme complexes are structurally constructed is outlined using the example of two acyl-CoA dehydrogenase/electron-transferring flavoproteins.

Living cells are coated and structured by lipid membranes. We addressed two important questions: how are membranes shaped into their often unusual forms, and how do cells monitor the membrane state? With molecular and coarse-grained simulations, we could show how the proteins Mga2 and Ire1 can sense the state of the endoplasmic reticulum. Also, new insights have been obtained about the fusion of vesicles, the formation of tubular structures in the endoplasmic reticulum, and the induction of autophagosomes aided by the Atg1 complex.

We determined the structure of a complete, dimeric F₁F_o-ATP synthase from mitochondria of the yeast Yarrowia lipolytica by a combination of cryo-electron microscopy (cryo-EM) and X-ray crystallography. The structure resolves 58 of the 60 subunits in the dimer. Horizontal helices of subunit a in F_o wrap around the c-ring rotor, and a total of six vertical helices assigned to subunits a, b, f, i, and 8 span the membrane. Our data explain the structural basis of cristae formation in mitochondria, a landmark signature of eukaryotic cell morphology.

Molecular oxygen appeared in the atmosphere about three billion years ago. Nature developed two membrane integrated enzymatic systems which reduce oxygen to water and use the energy of this reaction to produce biologically important energy carriers. These enzymes are the haem-copper terminal oxidases, e.g. cytochrome c oxidase, and the bd oxidases. The atomic structures of representative members of both enzyme families were determined. These evolutionary unrelated enzymes apparently use the same mechanisms to conserve energy and to prevent the formation of toxic reactive oxygen species.