InstructThe latest webinar in the Instruct-ERIC Structure Meets Function series is hosted by Instruct-FR2. The webinar series offers an insight into the very cutting edge of structural biology research, utilising the latest techniques available through Instruct-ERIC facilities and centres.
This month we will have two speakers who have accessed the IBS Grenoble facility at Instruct-FR2. Find out more about the technologies available at the centre, and the expert contacts who can help with your research project.
The webinar will take place 11:00-12:00 CET, on 19 March. Watch the recording here.
Moderator: Martin Blackledge - Instruct-FR2 (IBS Grenoble)
Speaker 1: Vincent Chaptal - Institut de Biologie et Chimie des Protéines, Lyon
Talk Title: Plasticity in the mutidrug ABC transporter BmrA as a base to handle multiple substrates, and how substrates can modulate it for a more efficient use of ATP.
Speaker 2: Barbara Zambelli - Università di Bologna
Talk Title: Dissecting the structure of the nickel binding site of HypA•UreE2 complex required for urease maturation
Abstract: Urease is a nickel-dependent enzyme exploited by many virulent bacteria and fungi to infect the host and exert their virulence. Its maturation pathway requires the protein UreE as a metallochaperone to supply Ni(II) ions to the enzyme. In Helicobacter pylori urease maturation also requires HypA, an accessory protein that is commonly associated with nickel-dependent hydrogenase activation. HypA and UreE dimer (UreE2) form a complex that is functional for metal ion delivery. This complex forms in the absence of Ni(II) and brings Ni(II) binding residues of UreE2 and HypA in close proximity. In the present work, the nature of this metal binding site and the residues that are involved in Ni(II) binding will be investigated. The Ni-binding properties of HypA and UreE2, as well as of their complex HypA•UreE2, were investigated by isothermal titration calorimetry (ITC) using a global fitting strategy that included all the relevant equilibria. This analysis showed that the protein complex contains a single Ni(II)-binding site with a sub-nanomolar KD, not present in the isolated proteins. The structural features of this novel Ni(II) site were elucidated using proteins produced with specifically deuterated amino acids, protein point mutations, and the analyses of hyperfine shifted NMR features, as well as molecular modeling. The results show that the complex contains a six-coordinate, high-spin Ni(II) site with ligands provided by both component proteins.
