1xfv: Difference between revisions
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|PDB= 1xfv |SIZE=350|CAPTION= <scene name='initialview01'>1xfv</scene>, resolution 3.35Å | |PDB= 1xfv |SIZE=350|CAPTION= <scene name='initialview01'>1xfv</scene>, resolution 3.35Å | ||
|SITE= | |SITE= | ||
|LIGAND= <scene name='pdbligand= | |LIGAND= <scene name='pdbligand=3AT:3'-DEOXYADENOSINE-5'-TRIPHOSPHATE'>3AT</scene>, <scene name='pdbligand=CA:CALCIUM+ION'>CA</scene>, <scene name='pdbligand=MG:MAGNESIUM+ION'>MG</scene> | ||
|ACTIVITY= [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] | |ACTIVITY= <span class='plainlinks'>[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] </span> | ||
|GENE= cya ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=1392 Bacillus anthracis]) | |GENE= cya ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=1392 Bacillus anthracis]) | ||
|DOMAIN= | |||
|RELATEDENTRY=[[1xfu|1XFU]], [[1xfw|1XFW]], [[1xfx|1XFX]], [[1xfy|1XFY]], [[1xfz|1XFZ]] | |||
|RESOURCES=<span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1xfv FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1xfv OCA], [http://www.ebi.ac.uk/pdbsum/1xfv PDBsum], [http://www.rcsb.org/pdb/explore.do?structureId=1xfv RCSB]</span> | |||
}} | }} | ||
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==Overview== | ==Overview== | ||
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. | 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. | ||
==About this Structure== | ==About this Structure== | ||
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[[Category: Tang, W J.]] | [[Category: Tang, W J.]] | ||
[[Category: Zhukovskaya, N L.]] | [[Category: Zhukovskaya, N L.]] | ||
[[Category: protein-protein interaction]] | [[Category: protein-protein interaction]] | ||
''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Mon Mar 31 00:49:03 2008'' | ||
