Sandbox Reserved 1489: Difference between revisions
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=='''2JLN'''== | =='''2JLN'''== | ||
<StructureSection load='1stp' size='340' side='right' caption='Caption for this structure' scene=''> | <StructureSection load='1stp' size='340' side='right' caption='Caption for this structure' scene=''> | ||
2JLN is one of the conformations of Mhp1, which is a membrane secondary transporter.<ref>PMID 18927357</ref> | 2JLN is one of the conformations of Mhp1, which is a membrane secondary transporter. | ||
The main information of this Proteopedia page come from the article : Structure and Molecular Mechanism of a Nucleobase-Cation-Symport-1 Family Transporter.<ref>PMID 18927357</ref> | |||
== '''Function''' == | == '''Function''' == | ||
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The central bundle is composed of TMs 1 and 2, twined to the TMs 6 and 7 respectively. In addition, the protein presents a V-shape structure formed by TMs 3 to 5, twined to TMs 8 to 10 (''Figure 2''). | The central bundle is composed of TMs 1 and 2, twined to the TMs 6 and 7 respectively. In addition, the protein presents a V-shape structure formed by TMs 3 to 5, twined to TMs 8 to 10 (''Figure 2''). | ||
TM5 and TM10 are 'flexible helices' because they bend during the state transitions.<ref | TM5 and TM10 are 'flexible helices' because they bend during the state transitions.<ref name="art2" /> | ||
The substrate- and cation-binding sites are located in the space between the central four-helix-bundle and the outer helix layer. | The substrate- and cation-binding sites are located in the space between the central four-helix-bundle and the outer helix layer. | ||
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Experiments have shown that sodium increases the affinity of benzyl-hydantoin for Mhp1 and reciprocally benzyl-hydantoin increases the affinity of sodium for Mhp1. | Experiments have shown that sodium increases the affinity of benzyl-hydantoin for Mhp1 and reciprocally benzyl-hydantoin increases the affinity of sodium for Mhp1. | ||
Indeed, the presence of benzyl-hydantoin in Mhp1 binding site blocks the pathway of the sodium ion to the extracellular side.<ref | Indeed, the presence of benzyl-hydantoin in Mhp1 binding site blocks the pathway of the sodium ion to the extracellular side.<ref name="art2" /> | ||
Therefore, the binding of the substrate and the cation are closely coupled. | Therefore, the binding of the substrate and the cation are closely coupled. | ||