title: Sequential binding of calcium ions to the B-repeat domain of SdrD from Staphylococcus aureus.
abstract: Biofilms of live bacteria forming on medical devices and implants contribute significantly to bacterial blood dissemination and to the spread of nosocomial infections. Cell surface SdrD protein plays a key role in the attachment of Staphylococcus aureus to the extracellular matrix (ECM) and in the formation of biofilm. SdrD binds calcium ions using its B1-B5 region bearing EF-hand Ca-binding sites, leading to conformational changes in the structure of SdrD. This alters the distance between the bacterial surface and the ECM-interacting domain of SdrD in a spring-like fashion, participating in bacterial attachment. In this study we investigated calcium binding to EF-hand sites of SdrD using isothermal titration calorimetry and determined the impact of this process on SdrD's thermodynamic stability. This allowed us to propose a model of B1-B5 reorganization upon binding of calcium and to get new insight into the molecular mechanism of SdrD's action.
authors.affiliation: a Aix-Marseille Université, Inserm, CRO2 UMR_S 911, Faculté de Pharmacie, 13385 Marseille, France.|b Institute of Physiologically Active Compounds, RAS, 142432 Chernogolovka, Russian Federation.
authors.forename: Andrei Yu
authors.initials: AY
authors.lastname: Roman
authors.affiliation: a Aix-Marseille Université, Inserm, CRO2 UMR_S 911, Faculté de Pharmacie, 13385 Marseille, France.
authors.forename: François
authors.initials: F
authors.lastname: Devred
authors.affiliation: c Engelhardt Institute of Molecular Biology, RAS, 119991 Moscow, Russian Federation.
authors.forename: Vladimir M
authors.initials: VM
authors.lastname: Lobatchov
authors.affiliation: c Engelhardt Institute of Molecular Biology, RAS, 119991 Moscow, Russian Federation.
authors.forename: Alexander A
authors.initials: AA
authors.lastname: Makarov
authors.affiliation: a Aix-Marseille Université, Inserm, CRO2 UMR_S 911, Faculté de Pharmacie, 13385 Marseille, France.
authors.forename: Vincent
authors.initials: V
authors.lastname: Peyrot
authors.affiliation: d Institute of General Pathology and Pathophysiology, RAMS, 125315 Moscow, Russian Federation.
authors.forename: Aslan A
authors.initials: AA
authors.lastname: Kubatiev
authors.affiliation: a Aix-Marseille Université, Inserm, CRO2 UMR_S 911, Faculté de Pharmacie, 13385 Marseille, France.|d Institute of General Pathology and Pathophysiology, RAMS, 125315 Moscow, Russian Federation.
authors.forename: Philipp O
authors.initials: PO
authors.lastname: Tsvetkov
mesh_terms: D001426:Bacterial Proteins / Q000737:chemistry / Q000378:metabolism*; D002118:Calcium / Q000378:metabolism*; D002135:Calcium-Binding Proteins / Q000737:chemistry / Q000378:metabolism*; D000072417:Protein Domains; D013816:Thermodynamics
chemical_list: D001426:Bacterial Proteins; D002135:Calcium-Binding Proteins; C115915:SdrD protein, Staphylococcus aureus; D002118:Calcium
keywords: Staphylococcus aureus; calcium binding; calorimétrie à balayage différentiel; calorimétrie à titrage isotherme; differential scanning calorimetry; dénaturation thermique de protéines; isothermal titration calorimetry; liaison au calcium; modèle de liaison séquentiel; protein thermal denaturation; sequential binding model