VISUALIZATION OF CALCIUM-TRANSPORT REGULATORY MECHANISMS

Adenosine triphosphate (ATP) drives many critical cellular processes. We will use laser-induced release from a caged, inactive form of ATP followed by short X-ray pulses at the dedicated time-resolved X-ray solution scattering (TR-XSS) beamline ID09 at ESRF-EBS to study protein conformational change in real time. We aim to track how domain movements and kinetics in a bacterial calcium-transporting P-type ATPase (LMCA1) are regulated by lipid chemistry and pH levels. Lipids modulate membrane protein function, but the connection between lipid chemistry and reaction cycle kinetics and dynamics is not well understood. Survival of pathogenic bacteria under basic conditions depends critically on Ca2+ transport. Therefore, structural and kinetic mapping of pH-dependent LMCA1 dynamics can potentially provide clues to better understand the structural basis of infection processes. Overall, the results will provide better understanding of lipid- and pH-induced regulation of calcium transport.