![Figure 1. The allosteric gating model of RYR2 activation by ATP. All channel transitions are reversible and obey the principle of detailed balance. From left to right, the states of the channel differ by fractional ATP occupancy (ATP-free monomers, ATP-bound monomers of the closed state [top row], and ATP-bound monomers of the open state [bottom row] are depicted in light gray, gray, and dark gray, respectively). The equilibrium constants of the microscopic ATP-binding reaction (i.e., that related to a single monomer and not to the whole tetramer) to the first monomer of the closed and open channel are given above the respective arrows. The open probability of the fully ATP-free and ATP-bound channels is given at the left and right margin, respectively.](https://cdn.rupress.org/rup/content_public/journal/jgp/140/2/10.1085_jgp.201110708/4/jgp_201110708_fig1.jpeg?Expires=1767688240&Signature=dtKBms8zbGRyrDagmc4dWCL9m772~xV6Se4Z8oT17gg-LlIUSw~gk-VYsXTQp~aJvx6vbInItjaHqNReSOfBQ8nK-l-XuNSlVDZbTz9OVZp55pscyEUOS~ccfFPMB53BkvHsOfewNZy6tFOU3Wkktj~4Dlk-hPI1mjT4QNQE6pSsxCaLO5DqN170rTU08XikUBl1mgM5Zu78jf8SPsEp3wfLEaNyPA8tF~vzOMHPyfRvhhVACmyU6LSe-rHxxgj4O3Y3v8hZxFESc8U7B7we9RY9PxSFNGwkdmw1WBzBbxkVKXhtdUEAZKulp~ysBcHW0lGjLfvuu5VLqPED3-vDWw__&Key-Pair-Id=APKAIE5G5CRDK6RD3PGA)
The allosteric gating model of RYR2 activation by ATP. All channel transitions are reversible and obey the principle of detailed balance. From left to right, the states of the channel differ by fractional ATP occupancy (ATP-free monomers, ATP-bound monomers of the closed state [top row], and ATP-bound monomers of the open state [bottom row] are depicted in light gray, gray, and dark gray, respectively). The equilibrium constants of the microscopic ATP-binding reaction (i.e., that related to a single monomer and not to the whole tetramer) to the first monomer of the closed and open channel are given above the respective arrows. The open probability of the fully ATP-free and ATP-bound channels is given at the left and right margin, respectively.
