Sandbox Reserved 1606: Difference between revisions
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After substrates bind in Cavity 1, ATP binds each NBD leading to the transporter shifting from inward-facing to outward-facing. The outward-facing conformation results in the <scene name='83/832932/Atp_bound_cavity_2/3'>collapse of Cavity 1</scene> in the TMD which closes Cavity 1 to the cytosol and forces the substrate to move forward to Cavity 2 as there is no longer room in Cavity 1 to accommodate substrates.<ref name="Manolaridis"/> <scene name='83/832932/Atp_bound_use_cav_2/2'>Cavity 2</scene>, which is occluded when the protein in is the inward-facing conformation, is now open to the extracellular space and able to release the substrate. Cavity 2 contains a less hydrophobic environment and, as a result, substrates are released due to hydrophobic mismatch.<ref name="Taylor"/> <scene name='83/832932/Atp_bound_use_el_disulfides/3'>Disulfide bonds</scene> in the external loops near the exit of Cavity 2 also help promote substrate release.<ref name="Manolaridis"/> Once Cavity 2 is empty, the protein reverts to the inward-facing conformation via hydrolysis of ATP. | After substrates bind in Cavity 1, ATP binds each NBD leading to the transporter shifting from inward-facing to outward-facing. The outward-facing conformation results in the <scene name='83/832932/Atp_bound_cavity_2/3'>collapse of Cavity 1</scene> in the TMD which closes Cavity 1 to the cytosol and forces the substrate to move forward to Cavity 2 as there is no longer room in Cavity 1 to accommodate substrates.<ref name="Manolaridis"/> <scene name='83/832932/Atp_bound_use_cav_2/2'>Cavity 2</scene>, which is occluded when the protein in is the inward-facing conformation, is now open to the extracellular space and able to release the substrate. Cavity 2 contains a less hydrophobic environment and, as a result, substrates are released due to hydrophobic mismatch.<ref name="Taylor"/> <scene name='83/832932/Atp_bound_use_el_disulfides/3'>Disulfide bonds</scene> in the external loops near the exit of Cavity 2 also help promote substrate release.<ref name="Manolaridis"/> Once Cavity 2 is empty, the protein reverts to the inward-facing conformation via hydrolysis of ATP. | ||
Cavities 1 and 2 are separated by a <scene name='83/832932/Leucine_plug_open_con/7'>leucine plug</scene> which likely acts as a substrate check-point during transport; changes to either of these leucine residues have exhibited an increase in transport and a decrease in substrate specificity.<ref name="Manolaridis"/> After the substrate binds Cavity 1 and ATP molecules bind each NBD, the <scene name='83/832932/Atp_bound_cavsleu/ | Cavities 1 and 2 are separated by a <scene name='83/832932/Leucine_plug_open_con/7'>leucine plug</scene> which likely acts as a substrate check-point during transport; changes to either of these leucine residues have exhibited an increase in transport and a decrease in substrate specificity.<ref name="Manolaridis"/> After the substrate binds Cavity 1 and ATP molecules bind each NBD, the <scene name='83/832932/Atp_bound_cavsleu/5'>leucine plug opens</scene> to allow the substrate to enter Cavity 2. Once the substrate enters Cavity 2, the plug is able to reform and promote substrate release and conversion to the inward-facing conformation. | ||
==Disease== | ==Disease== | ||
