Chloride Intracellular Channel Protein 2: Difference between revisions
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Actually, the exhibited long loop is flexible and easily affected by crystal packing. When we analyze CLIC2’s electrostatic potential surface, we can observe that contrary to the cavity between the N- and C-terminal domains that is positively charged, the foot loop is negatively charged due to its six acid residues. Indeed, this loop has a crucial functional role; it can be considered as an anchor between CLIC2 and other protein. This foot loop can be inserted into a groove of a neighboring molecule thanks to electrostatic charges. The negative charges provided by the acid resides allow the foot loop to insert into positively charged cavity of another symmetry-related molecule. What’s more, there is an Asp in the 161 position that can form a salt bridge with a Lys from a neighbor molecule, thus the interaction between protein-protein will be increased. Then, the CXXC motif, close to the cavity can provide extensive hydrogen bonds which will stabilize again the interaction. We also can notice that hydrophobic interactions can be involved in the interaction with the highly conserved Ile 158 surrounded by Val 242, Tyr 239 and the alkyl chain of Lys 125 in the groove. This foot loop is an evidence of a structure-function link: the equivalent region in the structurally GST family corresponds to the active site. We can then suggest that CLIC2 will interact with other protein such as the ryanodine receptor for example through the same interaction way. | Actually, the exhibited long loop is flexible and easily affected by crystal packing. When we analyze CLIC2’s electrostatic potential surface, we can observe that contrary to the cavity between the N- and C-terminal domains that is positively charged, the foot loop is negatively charged due to its six acid residues. Indeed, this loop has a crucial functional role; it can be considered as an anchor between CLIC2 and other protein. This foot loop can be inserted into a groove of a neighboring molecule thanks to electrostatic charges. The negative charges provided by the acid resides allow the foot loop to insert into positively charged cavity of another symmetry-related molecule. What’s more, there is an Asp in the 161 position that can form a salt bridge with a Lys from a neighbor molecule, thus the interaction between protein-protein will be increased. Then, the CXXC motif, close to the cavity can provide extensive hydrogen bonds which will stabilize again the interaction. We also can notice that hydrophobic interactions can be involved in the interaction with the highly conserved Ile 158 surrounded by Val 242, Tyr 239 and the alkyl chain of Lys 125 in the groove. This foot loop is an evidence of a structure-function link: the equivalent region in the structurally GST family corresponds to the active site. We can then suggest that CLIC2 will interact with other protein such as the ryanodine receptor for example through the same interaction way. | ||
NB: | NB: two crystal forms are obtained differencing by their foot loop position due to limited hydrogen bonding. | ||
== Links between CLIC2 and the other CLICs and the GST superfamily members == | == Links between CLIC2 and the other CLICs and the GST superfamily members == | ||
