Structural biology aims to elucidate the mechanisms of biological molecules (proteins, RNA,
DNA, etc.) at the level of single atoms. Since its inception in the 1950s, it has been
dominated by protein crystallography. Over the last decade, however, this field has
undergone a dramatic transformation with the development of high-resolution cryo-electron
microscopy (cryo-EM) and AI-based computational methods, such as AlphaFold. The focus
has also shifted from static images of macromolecules to dynamic descriptions involving
mobility and conformational changes.
In this talk, I will discuss new developments in structural biology. I will illustrate these
developments using our recent work on DNA repair in bacteria, focusing on two pathways:
nucleotide excision repair (NER) and homologous recombination (HR). I will describe the
mechanism of UvrA, which senses DNA modifications in NER. UvrA employs an unusual
mechanism that uses ATP energy to mechanically probe DNA integrity 1 . For HR I will discuss
the mechanism the RecFOR complex involved in the early staged of the pathway 2 . I will also
describe RuvC, a nuclease that cleaves four-way DNA structures (Holliday junctions) at the
end of homologous recombination. This enzyme uses conformational dynamic probing of DNA to identify the proper sequence for cutting 3 . The aim of the presentation is to provide a
description of the current status of the field and its future prospects.
20 Marzo, 2026