markerProfessor Eva Nogales, University of California, Berkeley, Lawrence Berkeley Labs

Dr. Eva Nogales carried out her bachelor studies in Physics at the Universidad Autónoma de Madrid. During her graduate work at the Synchrotron Radiation source in the UK, she used SAXS and cryo-EM to investigate the assembly of tubulin polymers in the presence of different anti-mitotic drugs. Her postdoctoral work in the lab of Ken Downing at the Lawrence Berkeley National Lab (LBNL) produced the first atomic structure of tubulin using electron crystallography. She joined the Molecular and Cell Biology faculty at UC Berkeley in 1998. Since 2000 she has been an HHMI Investigator. Presently she is Professor and Head in the Biochemistry, Biophysics and Structural Biology Division of the MCB Department at UC Berkeley, where she studies cytoskeletal proteins and gene regulatory complexes using cryo-EM. She is also a Senior Faculty Scientist at LBNL.

 

Monday, May 1, 2017 at 4:00 pm

Location: Benjamin Banneker Room, Stamp Student Union
Title: “Visualization of the Human Transcription Initiation Machinery”

picture1Eukaryotic gene transcription requires the assembly at the promoter of a large pre-initiation complex (PIC) that includes RNA polymerase II (Pol II) and the general transcription factors TFIID, TFIIA, TFIIB, TFIIF, TFIIE, and TFIIH. The size and complexity of Pol II, TFIID, and TFIIH have precluded their reconstitution from heterologous systems, and purification relies on scarce endogenous sources. Together with their conformational flexibility and the transient nature of their interactions, these limitations had precluded structural characterization of the PIC. In the last few years, however, progress in cryo–electron microscopy (cryo-EM) has made possible the visualization, at increasingly better resolution, of large PIC assemblies in different functional states. These structures can now be interpreted in near-atomic detail and provide an exciting structural framework for past and future functional studies, giving us unique mechanistic insight into the complex process of transcription initiation.

Tuesday, May 2, 2017 at 11:00 am

Location: Marker Seminar Room 0112, Chemistry & Biochemistry Complex
Title: “Structural Basis of Microtubule Dynamic Instability and its Regulation”

picture2Microtubules (MTs) are crucial components of the cytoskeleton and play a central role in cell division. Essential to MT function is the property of dynamic instability, the stochastic switching between MT growing and shrinking linked to GTP binding and hydrolysis MT dynamics are tightly regulated in vivo by a number of MT-associated proteins (MAPs), while widely successful anti-mitotic chemotherapeutics, such as Taxol, bind to and stabilize MTs, inhibiting dynamic instability and preventing cells from dividing. Structural studies of microtubule in different nucleotide states, and bound to different MAPs or drugs are important to generate a mechanistic understanding of the regulated function of MTs. As non-crystallizable polymers, MT have been the target of cryo-electron microscopy (cryo-EM) studies since the technique was first established. Over the years, image processing strategies have been developed that take care of the unique, pseudo-helical symmetry of the microtubule. With recent progress in data quality and data processing, cryo-EM reconstructions are now reaching resolutions that allow the generation of atomic models of microtubules and the factors that bind them.

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