Jannik Strauss, ESR4

Jannik Strauss is ESR4, works at the University of Leeds, UK. Her PhD subject is “Novel Approaches to Proton Pumping Pyrophosphatases”

Passbild-JannikPlease tell us about yourself:

I grew up in a small town close to Hannover in Germany. After I finished school, I worked at the Institute of Microbiology and Hospital Hygiene of Nordstadt Hospital in Hannover for one year, where I helped identifying disease-causing microbes in patient samples. It was during that time that I found my passion for infectious disease research. To better understand diseases on a molecular level I decided to study Biochemistry and finished my Master at the Hannover Medical School in 2016. During my Masters I started to focus on structural biology as it can greatly contribute to our understanding of what is going on in biological systems by showing us the three-dimensional structures of its components. Besides that, I find working with huge machines like synchrotrons to shoot at protein crystals with x-rays really cool. My study programme allowed me to visit the Institute of Structural Biology at the University of Auckland (New Zealand) for five months which was when I discovered the benefits and fun that come along with working in an internationally active field of science. Before starting my PhD in Leeds and continuing with my academic pathway, I wanted to get to know the industrial side of research, which is why I joined the Crystallography Department of Merck at their headquarters in Darmstadt (Germany) for half a year. If I am not in the lab working on my yet to come breakthrough, I enjoy doing sports like bouldering where you are actually surrounded by other PhD students – it seems to be their sports.

Why are you interested in science?

I guess it started with a German journal called “Spektrum der Wissenschaften” that aims to act as intermediary between scientific publications of all fields and the interested public, which my father always read. So, when I was younger I read about quarks and other particles, mathematical problems no one could solve, black holes and bacterial defence systems and all of this fascinated me. I started questioning why and how things work and was amazed by the solutions people found to answer the questions they had. From that time on I wanted to be one of those who are looking for answers no one knows the answer to – in other words, a scientist.

Please tell us about your PhD project:

My PhD project is about membrane-bound pyrophosphatases (mPPase). Those are enzymes that cleave a molecule called pyrophosphate (PPi) and use the energy stored in this molecule to pump sodium (Na+) and/or proton (H+) ions across membranes. They can be found in a variety of organisms such as bacteria, parasites or plants but are absent in any multicellular animals including humans. mPPases are very important for the resistance to stress in the organisms they are found in. For example, the concentration difference of Na+ and/or H+ between one and the other side of the membrane (as established by mPPases) can be used to provide some extra energy for the organism during periods of low-energy.

We aim to understand the way mPPases work by revealing their three-dimensional structure at atomic resolutions using x-ray crystallography. As the name implies x-ray crystallography requires crystals – in our case protein crystals.

Figure Jannik
Schematic reaction mechanism of a membrane embedded mPPase with Na+ represented by purple and H+ represented by grey spheres

In order to grow those, you need ultra-pure protein which is one of the challenges you always face working in this field. Once you managed to crystallise your protein (mPPase), you will shoot the crystals with super bright x-rays that are generated in special particle accelerators called synchrotrons. Synchrotrons are like microscopes that use x‑rays, not visible light, and computers, not lenses. Scientists already managed to solve some structures of mPPases; however, we still do not fully understand how it works. One of several questions that remain unanswered is how mPPases select the ions they transport across membranes, which is also called ion-selectivity. Some mPPases pump Na+, whereas other pump H+ and yet others pump both. A structure of a dual pumping mPPase (pumps Na+ and H+) would help us understand how this works. And there are many more things we are working on like getting a complete picture of the catalytic cycle of mPPases, which is basically all the different three-dimensional shapes (conformations) a protein goes through during its reaction. Here, time-resolved crystallography can help us getting there, for more information check out Diogo’s portrait (ESR8).

What do you or did you enjoy most until now in your position within RAMP network? Why ?

I am proud to be part of one of the prestigious Innovative Training Networks (ITNs) funded by the EU as I think these provide the perfect environment to kick-off your career in science. We already start our PhD with a supportive interdisciplinary network across Europe including not only academic but also a set of world leading industrial institutions. Having the chance of working in several different groups and countries is a great and valuable experience. One of my highlights was our RAMP kick-off meeting in Leeds where we met all the other students and supervisors and discussed our aims and future challenges. Also, being part of a group of PhD students all starting at the same time and facing similar problems helps to settle in and not to be afraid of all the challenges yet to come. Finally, you start off with a bunch of friends all across Europe you can visit for vacation. What could be better?