Dyamic instability, an essential property of microtubules, is an intrinsic attribute of tubulin linked to the binding and hydrolysis of GTP. We are particularly interested in the structural intermediates in the process of microtubule assembly and disassembly and how they are utilized in the cell... read more

A growing number of cellular factors are being found to regulate and/or utilize the dynamic behavior of microtubules during the cell cycle. We are studying kinetochore components, such as the Dam1 and Ndc80 complexes, their interaction with microtubules, and their cellular regulation... read more

Septins are conserved GTases defining a new type of cytoskeletal filaments essential in cytokinesis and other membrane-remodeling processes. We are studying the yeast mitotic septins (Cdc3, Cdc10, Cdc11, Cdc12 and Shs1) to define the organization of the septin assembly unit, its polymerization and its regulation... read more

During cell division, initiator proteins target and bind to DNA replication origins to trigger genome duplication. We are characterizing the structure of Drosophila melanogaster Origin Recognition Complex (DmORC), and the effect of nucleotide and phosphorylation state in conformation and function... read more

Regulated gene transcription in eukaryotes requires the assembly of a complex molecular machinery that includes general factors, activators, cofactor complexes and chromatin remodeling factors. We are interested in characterizing the structure of these different components and how they interact to regulate transcription. Read more about RSC...   Read more about PBAF...   Read more about TFIID...   Read more about RNAPII...

In eukaryotes at least twelve translation initiation factors and an mRNA methylated G-cap are required to initiate protein synthesis, while in many viruses a structured RNA element replaces most of those factors. We are studying the molecular interplays that characterize both initiation pathways... read more

The eukaryotic exosome is a conserved complex important for 3' end trimming and degradation of RNA. In yeast, the Rrp44 protein constitutively associates with the nine-subunit core exosome and provides the sole sources of processive 3'-to-5' exoribonuclease activity. We have obtained EM reconstructions of the core and Rrp44-bound exosome complexes... read more

Our lab is part of a large NCI funded project in Structural Biology of DNA Repair that aims at producing biologically relevant DNA repair structures and identifying fundamental structural principles for repair proteins. The role of electron microscopy is to provide structures of large macromolecular complexes involved in these processes... read more