2a74: Difference between revisions
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|PDB= 2a74 |SIZE=350|CAPTION= <scene name='initialview01'>2a74</scene>, resolution 2.40Å | |PDB= 2a74 |SIZE=350|CAPTION= <scene name='initialview01'>2a74</scene>, resolution 2.40Å | ||
|SITE= | |SITE= | ||
|LIGAND= <scene name='pdbligand= | |LIGAND= <scene name='pdbligand=GOL:GLYCEROL'>GOL</scene>, <scene name='pdbligand=NAG:N-ACETYL-D-GLUCOSAMINE'>NAG</scene>, <scene name='pdbligand=NO3:NITRATE+ION'>NO3</scene> | ||
|ACTIVITY= | |ACTIVITY= | ||
|GENE= | |GENE= | ||
|DOMAIN= | |||
|RELATEDENTRY= | |||
|RESOURCES=<span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=2a74 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2a74 OCA], [http://www.ebi.ac.uk/pdbsum/2a74 PDBsum], [http://www.rcsb.org/pdb/explore.do?structureId=2a74 RCSB]</span> | |||
}} | }} | ||
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==Overview== | ==Overview== | ||
The mammalian complement system is a phylogenetically ancient cascade system that has a major role in innate and adaptive immunity. Activation of component C3 (1,641 residues) is central to the three complement pathways and results in inflammation and elimination of self and non-self targets. Here we present crystal structures of native C3 and its final major proteolytic fragment C3c. The structures reveal thirteen domains, nine of which were unpredicted, and suggest that the proteins of the alpha2-macroglobulin family evolved from a core of eight homologous domains. A double mechanism prevents hydrolysis of the thioester group, essential for covalent attachment of activated C3 to target surfaces. Marked conformational changes in the alpha-chain, including movement of a critical interaction site through a ring formed by the domains of the beta-chain, indicate an unprecedented, conformation-dependent mechanism of activation, regulation and biological function of C3. | The mammalian complement system is a phylogenetically ancient cascade system that has a major role in innate and adaptive immunity. Activation of component C3 (1,641 residues) is central to the three complement pathways and results in inflammation and elimination of self and non-self targets. Here we present crystal structures of native C3 and its final major proteolytic fragment C3c. The structures reveal thirteen domains, nine of which were unpredicted, and suggest that the proteins of the alpha2-macroglobulin family evolved from a core of eight homologous domains. A double mechanism prevents hydrolysis of the thioester group, essential for covalent attachment of activated C3 to target surfaces. Marked conformational changes in the alpha-chain, including movement of a critical interaction site through a ring formed by the domains of the beta-chain, indicate an unprecedented, conformation-dependent mechanism of activation, regulation and biological function of C3. | ||
==About this Structure== | ==About this Structure== | ||
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[[Category: Raaijmakers, H C.A.]] | [[Category: Raaijmakers, H C.A.]] | ||
[[Category: Roos, A.]] | [[Category: Roos, A.]] | ||
[[Category: immune system]] | [[Category: immune system]] | ||
''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 01:48:43 2008'' | ||
