Structural Biology of DNA Replication

 Structural Biology of DNA Replication
 

We apply molecular and structural biology tools to study the basic genetic processes within the cell and to characterise some of the proteins involved.

Structural biology is an interdisciplinary research area, requiring expertises from both the life sciences and the physical sciences. We use macromolecular crystallography to determine the atomic structure of these proteins, as well as biochemical and biophysical approaches to understand how they function. Crystallographic studies are complemented by the concomitant use of electron microscopy to visualise the architecture of large complexes and/or small-angle X-ray scattering (SAXS) to obtain additional structural information. The laboratory benefits from the close proximity of the Elettra synchrotron beamlines, and state-of-the-art facilities for protein expression and automatic crystallisation.

Our research is mainly centred on the structural characterisation of proteins and protein complexes involved in the process of DNA replication in eukaryotic cells. Eukaryotic DNA replication is a highly coordinated and tightly regulated process. Due to the large genome size, eukaryotic cells initiates DNA replication at multiple origins and complex networks of proteins, under strict cell-cycle control, are required to ensure that each origin is used only once and no segment of DNA is left un-replicated or undergoes multiple rounds of replication. Although recent genetic and genomic approaches have identified many of the key players, an understanding of their architecture and biochemical role of each component at the replication fork is still lacking. We are currently expressing, purifying and characterising a number of human proteins involved in DNA replication and repair, including the replicative MCM helicases, the accessory factors GINS and Cdc45, the human primase heterodimer, and the repair helicases RecQ1 and RecQ4.

Most of these proteins are expressed only in proliferating cells, being absent from quiescent and differentiated somatic cells, and are therefore good candidates for novel cancer biomarkers and putative drug targets.

written by Silvia Onesti This e-mail address is being protected from spambots. You need JavaScript enabled to view it.