The Wolf-Watz NMR-lab
The basic paradigm in structural biology is that protein function is dictated by the three-dimensional structure. However, under cellular conditions, time dependent fluctuations of protein structures (dynamics) and temporal interactions with other macromolecules (such as proteins, nucleic acids and membranes) are indispensable for functionality. In my laboratory we investigate the relation between protein structure and dynamics to function. Our main experimental technique is high resolution protein NMR spectroscopy in solution. However, complementary techniques such as protein engineering, circular dichroism, isothermal titration calorimetry, molecular dynamics simulations and functional assays are integrated and essential in our research. We have three main research interests: (1) The role of enzyme dynamics in enzymatic catalysis, (2) Structure and dynamics of proteins that control infectivity in the bacterium Yersinia pseudotuberculosis, and (3) Interactions between chaperones and folded protein substrates .
Open positions We have an opening for a two-year postdoctoral position in protein NMR (posted 2011-12-01), please call or email to inquire.
Key words NMR, enzyme, dynamics, function, mechanism
Research
Enzyme dynamics. Structural flexibility is many cases intimately linked to the function of proteins and enzymes. Traditionally enzyme mechanisms
have been deciphered by combining knowledge from static structures and kinetic measurements. In my lab we are interested in the time-dependent fluctuations of the enzyme and the coupling between fluctuations and function.
Adenylate kinase (adk) has emerged as one of the principal model systems to study the interplay between structure, dynamics and enzymatic activity. We have made several contributions to the understanding of conformational dynamics and activity in the adenylate kinase system. For example, we have shown that the ATP bound state of adk, in contrast to the traditional view of enzyme substrate complex
es as static low-entropy states, is extremely dynamic and interconverts between open and closed states. We have recently found that the mechanism of conformational change in response to ATP binding follow a "order-disorder-order" mechanism where specific segments unfold followed by refolding into the closed state.
Protein structure and dynamics in bacterial infections
Pathogenicity of the bacterium Yersinia pseudotuberculosis is dependent on translocation of effector proteins into eukaryotic host cells. The translocation process is accomplished with a multi-protein complex called the type III secretion system. Translocation is highly regulated and we study the structure and dynamics of proteins that are key regulatory players. One of our targets is YscU that is a membrane protein with a soluble cytosolic domain. Interestingly the soluble domain undergoes auto-proteolysis at a conserved NPTH motif. The protein structure can thus be viewed as a hetero-dimer. We are currently investigating the role of hetero-dimer dissociation with both biophysical and functional methods.
Chaperones, structure and interaction with folded substrates
The cell envelope of gram negative bacteria (such as E. coli) consists of inner and outer membranes separated with a periplasmatic space. Proteins localized to the inner membrane carry out a divergent array of essential cellular functions, such as nutrient uptake, cell division, signaling and trafficking of proteins and lipids. Proteins localized to the outer membrane are often embedded as β-barrels and their primary role is to mediate uptake of molecules by means of passive diffusion. Membrane proteins are inserted into the inner membrane by the action of the Sec translocon machinery. Proteins that are destined for the outer membrane are transported through the periplasmatic space with a dedicated chaperone network. We are investigating structure and interactions in this chaperone network.
Instrumentation
Bruker 500 MHz spectrometer
Bruker 600 MHz spectrometer with cryoprobe
Bruker 850 MHz spectrometer with cryoprobe (installation summer 2012)
Lab members
Jörgen Ådén, postdoc. jorgen.aden@chem.umu.se
Christoph F. Weise, postdoc. christoph.weise@chem.umu.se
Ho Ngoc Hoang Oanh, phD student, oanh.ho@chem.umu.se
Collaborators
Xavier Salvatella, Institute for Research in Biomedicine, Barcelona Spain.
Alexander Schug, Steinbuch Centre for Computing, Karlsruhe Institute of Technologie, Germany.
Daniel Daley, Department of Biochemistry and Biophysics, Stockholm University, Sweden.
Pernilla Wittung-Stafshede, Department of Chemistry, Umeå university, Sweden.
Hans Wolf-Watz, Department of Molecular Biology, Umeå University, Sweden
Contact Information
Magnus Wolf-Watz,
Assistant professor, Department of Chemistry
Department of Chemistry
Umeå University
SE-901 87
Sweden
magnus.wolf-watz@chem.umu.se
Office phone: +46-90-786 7690
Lab phone: +46-90-786 6576
