Biosketch

Prof. dr. Tessa Quax

Tessa Quax is a molecular microbiologist (PhD awarded 2013), who is interested in viruses infecting archaea, ubiquitous microorganisms that form a separate domain of life. Some archaea survive under extreme conditions (such as high salinity), while others play important roles in biochemical cycles or are present in the human gut. Archaeal viruses are known for their high structural diversity and studying them is important to understand the origin and evolution of viruses in general. Tessa aims to gain insight into the molecular mechanisms underlying the interaction between viruses and archaea. She uses haloarchaeal viruses as model, due to the availability of well developed molecular and cell biology tools for this system. With a combination of genetics, infection assays, light and electron microscopy, Tessa studies the infection mechanisms of archaeal viruses. Her main research areas include:

• The interaction between archaea and their viruses, with a special focus on processes occurring at the cell envelope, such as viral entry and egress.

• Method development to study archaeal cell biology, such as genetics and temperature-adapted light microscopy.

• The archaeal cell surface, and its role in motility and colonization of environments.

Three top-publications 2017-2022

1. Schwarzer S, Hackl T, Oksanen HM & Quax TEF (2023) Archaeal host cell recognition and viral binding of HFTV1 to its Haloferax host. mBio 14(1): e01833-22. DOI: https://doi.org/10.1128/mbio.01833-22

This paper describes the unusual binding mechanism of a tailed archaeal virus to its halophilic archaeal host.

2. Nussbaum F, Ithurbide S, Walsh J, Patro M, … Quax TEF* & Albers SV* (2020) An oscillating MinD protein determines the cellular positioning of motility machinery in archaea. Current Biology 30: 4956-4972 DOI: https://doi.org/10.1016/j.cub.2020.09.073

Application of cell biology tools to haloarchaea in order to gain insight into the function of ParA homologs in positioning of macromolecular complexes in archaeal cells.

3. Quax TEF, Altegoer F. Rossi F, Li Z, Rodriguez-Franco M, … & Albers S-V (2018). Structure and function of the archaeal response regulator CheY. Proceedings of the National Academy of Sciences USA. 115(6): E1259-E1268 DOI: https://doi.org/10.1073/pnas.1716661115

This work shows how the archaeal motility structure and chemotaxis system structurally interact to gain insight into how two modules with evolutionary different origins connect in archaeal cells.