ジャーナル: Sci Adv / 年: 2024 タイトル: Dephosphorylation and ion binding in prokaryotic calcium transport. 著者: Irfan Prabudiansyah / Fredrik Orädd / Konstantinos Magkakis / Kevin Pounot / Matteo Levantino / Magnus Andersson / 要旨: Calcium (Ca) signaling is fundamental to cellular processes in both eukaryotic and prokaryotic organisms. While the mechanisms underlying eukaryotic Ca transport are well documented, an understanding ...Calcium (Ca) signaling is fundamental to cellular processes in both eukaryotic and prokaryotic organisms. While the mechanisms underlying eukaryotic Ca transport are well documented, an understanding of prokaryotic transport remains nascent. LMCA1, a Ca adenosine triphosphatase (ATPase) from , has emerged as a prototype for elucidating structure and dynamics in prokaryotic Ca transport. Here, we used a multidisciplinary approach integrating kinetics, structure, and dynamics to unravel the intricacies of LMCA1 function. A cryo-electron microscopy (cryo-EM) structure of a Ca-bound E1 state showed ion coordination by Asp, Asn, and Glu. Time-resolved x-ray solution scattering experiments identified phosphorylation as the rate-determining step. A cryo-EM E2P state structure exhibited remarkable similarities to a SERCA1a E2-P* state, which highlights the essential role of the unique P-A domain interface in enhancing dephosphorylation rates and reconciles earlier proposed mechanisms. Our study underscores the distinctiveness between eukaryotic and prokaryotic Ca ATPase transport systems and positions LMCA1 as a promising drug target for developing antimicrobial strategies.