2l72
From Proteopedia
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<StructureSection load='2l72' size='340' side='right' caption='[[2l72]], [[NMR_Ensembles_of_Models | 10 NMR models]]' scene=''> | <StructureSection load='2l72' size='340' side='right' caption='[[2l72]], [[NMR_Ensembles_of_Models | 10 NMR models]]' scene=''> | ||
== Structural highlights == | == Structural highlights == | ||
| - | [[2l72]] is a 1 chain structure with sequence from [http://en.wikipedia.org/wiki/Toxoplasma_gondii Toxoplasma gondii]. Full experimental information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2L72 OCA]. <br> | + | <table><tr><td colspan='2'>[[2l72]] is a 1 chain structure with sequence from [http://en.wikipedia.org/wiki/Toxoplasma_gondii Toxoplasma gondii]. Full experimental information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2L72 OCA]. <br> |
| - | <b>Activity:</b> <span class='plainlinks'>[http://en.wikipedia.org/wiki/Glucokinase Glucokinase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=2.7.1.2 2.7.1.2] </span>< | + | </td></tr><tr><td class="sblockLbl"><b>Activity:</b></td><td class="sblockDat"><span class='plainlinks'>[http://en.wikipedia.org/wiki/Glucokinase Glucokinase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=2.7.1.2 2.7.1.2] </span></td></tr> |
| - | <b>Resources:</b> <span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=2l72 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2l72 OCA], [http://www.rcsb.org/pdb/explore.do?structureId=2l72 RCSB], [http://www.ebi.ac.uk/pdbsum/2l72 PDBsum]</span>< | + | <tr><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=2l72 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2l72 OCA], [http://www.rcsb.org/pdb/explore.do?structureId=2l72 RCSB], [http://www.ebi.ac.uk/pdbsum/2l72 PDBsum]</span></td></tr> |
| + | <table> | ||
| + | <div style="background-color:#fffaf0;"> | ||
== Publication Abstract from PubMed == | == Publication Abstract from PubMed == | ||
Toxoplasma gondii ADF (TgADF) belongs to a functional subtype characterized by strong G-actin sequestering activity and low F-actin severing activity. Among the characterized ADF/cofilin proteins, TgADF has the shortest length and is missing a C-terminal helix implicated in F-actin binding. In order to understand its characteristic properties, we have determined the solution structure of TgADF and studied its backbone dynamics from (15)N-relaxation measurements. TgADF has conserved ADF/cofilin fold consisting of a central mixed beta-sheet comprised of six beta-strands that are partially surrounded by three alpha-helices and a C-terminal helical turn. The high G-actin sequestering activity of TgADF relies on highly structurally and dynamically optimized interactions between G-actin and G-actin binding surface of TgADF. The equilibrium dissociation constant for TgADF and rabbit muscle G-actin was 23.81nM, as measured by ITC, which reflects very strong affinity of TgADF and G-actin interactions. The F-actin binding site of TgADF is partially formed, with a shortened F-loop that does not project out of the ellipsoid structure and a C-terminal helical turn in place of the C-terminal helix alpha4. Yet, it is more rigid than the F-actin binding site of Leishmania donovani cofilin. Experimental observations and structural features do not support the interaction of PIP2 with TgADF, and PIP2 does not affect the interaction of TgADF with G-actin. Overall, this study suggests that conformational flexibility of G-actin binding sites enhances the affinity of TgADF for G-actin, while conformational rigidity of F-actin binding sites of conventional ADF/cofilins is necessary for stable binding to F-actin. | Toxoplasma gondii ADF (TgADF) belongs to a functional subtype characterized by strong G-actin sequestering activity and low F-actin severing activity. Among the characterized ADF/cofilin proteins, TgADF has the shortest length and is missing a C-terminal helix implicated in F-actin binding. In order to understand its characteristic properties, we have determined the solution structure of TgADF and studied its backbone dynamics from (15)N-relaxation measurements. TgADF has conserved ADF/cofilin fold consisting of a central mixed beta-sheet comprised of six beta-strands that are partially surrounded by three alpha-helices and a C-terminal helical turn. The high G-actin sequestering activity of TgADF relies on highly structurally and dynamically optimized interactions between G-actin and G-actin binding surface of TgADF. The equilibrium dissociation constant for TgADF and rabbit muscle G-actin was 23.81nM, as measured by ITC, which reflects very strong affinity of TgADF and G-actin interactions. The F-actin binding site of TgADF is partially formed, with a shortened F-loop that does not project out of the ellipsoid structure and a C-terminal helical turn in place of the C-terminal helix alpha4. Yet, it is more rigid than the F-actin binding site of Leishmania donovani cofilin. Experimental observations and structural features do not support the interaction of PIP2 with TgADF, and PIP2 does not affect the interaction of TgADF with G-actin. Overall, this study suggests that conformational flexibility of G-actin binding sites enhances the affinity of TgADF for G-actin, while conformational rigidity of F-actin binding sites of conventional ADF/cofilins is necessary for stable binding to F-actin. | ||
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From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | ||
| + | </div> | ||
== References == | == References == | ||
<references/> | <references/> | ||
Revision as of 09:56, 1 May 2014
Solution structure and dynamics of ADF from Toxoplasma gondii (TgADF)
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