Journal:Acta Cryst D:S205979832001517X
From Proteopedia
(Difference between revisions)
| (10 intermediate revisions not shown.) | |||
| Line 7: | Line 7: | ||
In this study, a bacterial ASBT, called ASBT<sub>Yf</sub>, is engineered to have its intracellular parts connected by a disulfide bond, so that it will be trapped in an outward-facing state. Before this engineered ASBT<sub>Yf</sub> is trapped, it folds and moves like the wild-type protein. More importantly, it remains functional since it binds bile acids as normal. Then after the conformational trap, this ASBT<sub>Yf</sub> is found to open outwardly in its structure. In other words, a wild-type-like ASBT protein is trapped in a state facing outside of the cell, demonstrating that this outward-facing state is of physiological relevance. Meanwhile, a low-affinity ligand-like molecule, citrate, binds to the substrate-binding site in the trapped outward-facing ASBT structure, further indicating that the trapped ASBT protein retains its functionality. These data validate a physiological outward-facing state in ASBT, and advance out understanding toward its transport mechanism. | In this study, a bacterial ASBT, called ASBT<sub>Yf</sub>, is engineered to have its intracellular parts connected by a disulfide bond, so that it will be trapped in an outward-facing state. Before this engineered ASBT<sub>Yf</sub> is trapped, it folds and moves like the wild-type protein. More importantly, it remains functional since it binds bile acids as normal. Then after the conformational trap, this ASBT<sub>Yf</sub> is found to open outwardly in its structure. In other words, a wild-type-like ASBT protein is trapped in a state facing outside of the cell, demonstrating that this outward-facing state is of physiological relevance. Meanwhile, a low-affinity ligand-like molecule, citrate, binds to the substrate-binding site in the trapped outward-facing ASBT structure, further indicating that the trapped ASBT protein retains its functionality. These data validate a physiological outward-facing state in ASBT, and advance out understanding toward its transport mechanism. | ||
| + | |||
| + | <scene name='86/869943/Cv/6'>ASBT structure trapped in the outward-facing state by an engineered disulfide bond</scene> (PDB entry [[6lh1]]). Solvent can access the central binding pocket from outside of the cell. | ||
| + | |||
| + | *<scene name='86/869943/Cv/8'>Close-up of engineered disulfide bond</scene>. | ||
| + | |||
| + | <scene name='86/869943/Cv/9'>A ligand-like molecule, citrate, binds to the central binding pocket in the outward-facing ASBT</scene> (PDB entry [[6lh1]]), indicating this protein retains functionality. | ||
| + | |||
| + | '''PDB references:''' ASBTYf-Pair1Linked, Y113C/P190C mutant after disulfide cross-linking, [[6lh1]]; ASBTYf-Pair1Free, Y113C/P190C mutant before disulfide cross-linking, [[7cyg]]; ASBTYf-Pair2Free, V110C/I197C mutant before disulfide cross-linking, [[7cyk]]. | ||
<b>References</b><br> | <b>References</b><br> | ||
Current revision
| |||||||||||
This page complements a publication in scientific journals and is one of the Proteopedia's Interactive 3D Complement pages. For aditional details please see I3DC.
