1MD7

Monomeric structure of the zymogen of complement protease C1r

Summary for 1MD7

• Entry DOI: 10.2210/pdb1md7/pdb
• Related: 1GPZ 1MD8
• Descriptor: C1R COMPLEMENT SERINE PROTEASE, 2-acetamido-2-deoxy-beta-D-glucopyranose (3 entities in total)
• Functional Keywords: complement, innate immunity, serine protease, activation, substrate specificity, hydrolase
• Biological source: Homo sapiens (human)
• Total number of polymer chains: 1
• Total formula weight: 37275.12

Authors

Budayova-Spano, M.,Grabarse, W.,Thielens, N.M.,Hillen, H.,Lacroix, M.,Schmidt, M.,Fontecilla-Camps, J.,Arlaud, G.J.,Gaboriaud, C. (deposition date: 2002-08-07, release date: 2003-08-07, Last modification date: 2024-11-13)

Primary citation

Budayova-Spano, M.,Grabarse, W.,Thielens, N.M.,Hillen, H.,Lacroix, M.,Schmidt, M.,Fontecilla-Camps, J.,Arlaud, G.J.,Gaboriaud, C.
Monomeric structures of the zymogen and active catalytic domain of complement protease c1r: further insights into the c1 activation mechanism
Structure, 10:1509-1519, 2002

PubMed Abstract: C1r is the serine protease (SP) that mediates autoactivation of C1, the complex that triggers the classical complement pathway. We have determined the crystal structure of two fragments from the human C1r catalytic domain, each encompassing the second complement control protein (CCP2) module and the SP domain. The wild-type species has an active structure, whereas the S637A mutant is a zymogen. The structures reveal a restricted hinge flexibility of the CCP2-SP interface, and both are characterized by the unique alpha-helical conformation of loop E. The zymogen activation domain exhibits high mobility, and the active structure shows a restricted access to most substrate binding subsites. Further implications relevant to the C1r self-activation process are derived from protein-protein interactions in the crystals.

PubMed: 12429092
DOI: 10.1016/S0969-2126(02)00881-X

Experimental method

X-RAY DIFFRACTION (3.2 Å)