2i6s: Difference between revisions
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|PDB= 2i6s |SIZE=350|CAPTION= <scene name='initialview01'>2i6s</scene>, resolution 2.700Å | |PDB= 2i6s |SIZE=350|CAPTION= <scene name='initialview01'>2i6s</scene>, resolution 2.700Å | ||
|SITE= | |SITE= | ||
|LIGAND= <scene name='pdbligand=NAG:N-ACETYL-D-GLUCOSAMINE'>NAG</scene> | |LIGAND= <scene name='pdbligand=BMA:BETA-D-MANNOSE'>BMA</scene>, <scene name='pdbligand=FUL:BETA-L-FUCOSE'>FUL</scene>, <scene name='pdbligand=NAG:N-ACETYL-D-GLUCOSAMINE'>NAG</scene> | ||
|ACTIVITY= [http://en.wikipedia.org/wiki/Classical-complement-pathway_C3/C5_convertase Classical-complement-pathway C3/C5 convertase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.4.21.43 3.4.21.43] | |ACTIVITY= <span class='plainlinks'>[http://en.wikipedia.org/wiki/Classical-complement-pathway_C3/C5_convertase Classical-complement-pathway C3/C5 convertase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.4.21.43 3.4.21.43] </span> | ||
|GENE= C2a ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=9606 Homo sapiens]) | |GENE= C2a ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=9606 Homo sapiens]) | ||
|DOMAIN= | |||
|RELATEDENTRY=[[2i6q|2I6Q]] | |||
|RESOURCES=<span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=2i6s FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2i6s OCA], [http://www.ebi.ac.uk/pdbsum/2i6s PDBsum], [http://www.rcsb.org/pdb/explore.do?structureId=2i6s RCSB]</span> | |||
}} | }} | ||
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==Overview== | ==Overview== | ||
C2a provides the catalytic center to the convertase complexes of the classical and lectin-binding pathways of complement activation. We determined two crystal structures of full-length C2a, with and without a pseudo ligand bound. Both structures reveal a near-active conformation of the catalytic center of the serine protease domains, while the von Willebrand factor A-type domains display an intermediate activation state of helix alpha7 with an open, activated metal-ion-dependent adhesion site. The open adhesion site likely serves to enhance the affinity for the ligand C4b, similar to "inside-out" signaling in integrins. Surprisingly, the N-terminal residues of C2a are buried in a crevice near helix alpha7, indicative of a structural switch between C2 and C2a. Extended loops on the protease domain possibly envelop the protruding anaphylatoxin domain of the substrate C3. Together with a putative substrate-induced completion of the oxyanion hole, this may contribute to the high substrate specificity of the convertases. | C2a provides the catalytic center to the convertase complexes of the classical and lectin-binding pathways of complement activation. We determined two crystal structures of full-length C2a, with and without a pseudo ligand bound. Both structures reveal a near-active conformation of the catalytic center of the serine protease domains, while the von Willebrand factor A-type domains display an intermediate activation state of helix alpha7 with an open, activated metal-ion-dependent adhesion site. The open adhesion site likely serves to enhance the affinity for the ligand C4b, similar to "inside-out" signaling in integrins. Surprisingly, the N-terminal residues of C2a are buried in a crevice near helix alpha7, indicative of a structural switch between C2 and C2a. Extended loops on the protease domain possibly envelop the protruding anaphylatoxin domain of the substrate C3. Together with a putative substrate-induced completion of the oxyanion hole, this may contribute to the high substrate specificity of the convertases. | ||
==About this Structure== | ==About this Structure== | ||
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[[Category: Schouten, A.]] | [[Category: Schouten, A.]] | ||
[[Category: Vandeputte, D A.A.]] | [[Category: Vandeputte, D A.A.]] | ||
[[Category: serine protease domain]] | [[Category: serine protease domain]] | ||
[[Category: von willebrand factor-a domain]] | [[Category: von willebrand factor-a domain]] | ||
''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 03:40:36 2008'' | ||
