1xfx: Difference between revisions
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New page: left|200px<br /> <applet load="1xfx" size="450" color="white" frame="true" align="right" spinBox="true" caption="1xfx, resolution 3.20Å" /> '''Crystal structure o... |
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[[Image:1xfx.gif|left|200px]]<br /> | [[Image:1xfx.gif|left|200px]]<br /><applet load="1xfx" size="350" color="white" frame="true" align="right" spinBox="true" | ||
<applet load="1xfx" size=" | |||
caption="1xfx, resolution 3.20Å" /> | caption="1xfx, resolution 3.20Å" /> | ||
'''Crystal structure of anthrax edema factor (EF) in complex with calmodulin in the presence of 10 millimolar exogenously added calcium chloride'''<br /> | '''Crystal structure of anthrax edema factor (EF) in complex with calmodulin in the presence of 10 millimolar exogenously added calcium chloride'''<br /> | ||
==Overview== | ==Overview== | ||
Edema factor (EF), a key anthrax exotoxin, has an anthrax protective | Edema factor (EF), a key anthrax exotoxin, has an anthrax protective antigen-binding domain (PABD) and a calmodulin (CaM)-activated adenylyl cyclase domain. Here, we report the crystal structures of CaM-bound EF, revealing the architecture of EF PABD. CaM has N- and C-terminal domains and each domain can bind two calcium ions. Calcium binding induces the conformational change of CaM from closed to open. Structures of the EF-CaM complex show how EF locks the N-terminal domain of CaM into a closed conformation regardless of its calcium-loading state. This represents a mechanism of how CaM effector alters the calcium affinity of CaM and uncouples the conformational change of CaM from calcium loading. Furthermore, structures of EF-CaM complexed with nucleotides show that EF uses two-metal-ion catalysis, a prevalent mechanism in DNA and RNA polymerases. A histidine (H351) further facilitates the catalysis of EF by activating a water to deprotonate 3'OH of ATP. Mammalian adenylyl cyclases share no structural similarity with EF and they also use two-metal-ion catalysis, suggesting the catalytic mechanism-driven convergent evolution of two structurally diverse adenylyl cyclases. | ||
==Disease== | ==Disease== | ||
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==About this Structure== | ==About this Structure== | ||
1XFX is a [http://en.wikipedia.org/wiki/Protein_complex Protein complex] structure of sequences from [http://en.wikipedia.org/wiki/Bacillus_anthracis Bacillus anthracis] and [http://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens] with MG and CA as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Adenylate_cyclase Adenylate cyclase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=4.6.1.1 4.6.1.1] Full crystallographic information is available from [http:// | 1XFX is a [http://en.wikipedia.org/wiki/Protein_complex Protein complex] structure of sequences from [http://en.wikipedia.org/wiki/Bacillus_anthracis Bacillus anthracis] and [http://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens] with <scene name='pdbligand=MG:'>MG</scene> and <scene name='pdbligand=CA:'>CA</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Adenylate_cyclase Adenylate cyclase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=4.6.1.1 4.6.1.1] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1XFX OCA]. | ||
==Reference== | ==Reference== | ||
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[[Category: Guo, Q.]] | [[Category: Guo, Q.]] | ||
[[Category: Shen, Y.]] | [[Category: Shen, Y.]] | ||
[[Category: Tang, W | [[Category: Tang, W J.]] | ||
[[Category: Zhukovskaya, N | [[Category: Zhukovskaya, N L.]] | ||
[[Category: CA]] | [[Category: CA]] | ||
[[Category: MG]] | [[Category: MG]] | ||
[[Category: protein-protein interaction]] | [[Category: protein-protein interaction]] | ||
''Page seeded by [http:// | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 15:54:20 2008'' | ||
