View source for 1zjk

[[Image:1zjk.gif|left|200px]]<br /><applet load="1zjk" size="350" color="white" frame="true" align="right" spinBox="true" 
caption="1zjk, resolution 2.18&Aring;" />
'''Crystal structure of the zymogen catalytic region of human MASP-2'''<br />

==Overview==
Few reports have described in detail a true autoactivation process, where no extrinsic cleavage factors are required to initiate the autoactivation of a zymogen. Herein, we provide structural and mechanistic insight into the autoactivation of a multidomain serine protease: mannose-binding lectin-associated serine protease-2 (MASP-2), the first enzymatic component in the lectin pathway of complement activation. We characterized the proenzyme form of a MASP-2 catalytic fragment encompassing its C-terminal three domains and solved its crystal structure at 2.4 A resolution. Surprisingly, zymogen MASP-2 is capable of cleaving its natural substrate C4, with an efficiency about 10% that of active MASP-2. Comparison of the zymogen and active structures of MASP-2 reveals that, in addition to the activation domain, other loops of the serine protease domain undergo significant conformational changes. This additional flexibility could play a key role in the transition of zymogen MASP-2 into a proteolytically active form. Based on the three-dimensional structures of proenzyme and active MASP-2 catalytic fragments, we present model for the active zymogen MASP-2 complex and propose a mechanism for the autoactivation process.

==Disease==
Known disease associated with this structure: MASP2 deficiency OMIM:[[http://www.ncbi.nlm.nih.gov/entrez/dispomim.cgi?id=605102 605102]]

==About this Structure==
1ZJK is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1ZJK OCA]. 

==Reference==
A true autoactivating enzyme. Structural insight into mannose-binding lectin-associated serine protease-2 activations., Gal P, Harmat V, Kocsis A, Bian T, Barna L, Ambrus G, Vegh B, Balczer J, Sim RB, Naray-Szabo G, Zavodszky P, J Biol Chem. 2005 Sep 30;280(39):33435-44. Epub 2005 Jul 21. PMID:[http://ispc.weizmann.ac.il//pmbin/getpm?pmid=16040602 16040602]
[[Category: Homo sapiens]]
[[Category: Single protein]]
[[Category: Ambrus, G.]]
[[Category: Balczer, J.]]
[[Category: Barna, L.]]
[[Category: Bian, T.]]
[[Category: Gal, P.]]
[[Category: Harmat, V.]]
[[Category: Kocsis, A.]]
[[Category: Naray-Szabo, G.]]
[[Category: Sim, R B.]]
[[Category: Vegh, B.]]
[[Category: Zavodszky, P.]]
[[Category: beta barrel]]
[[Category: modular protein]]

''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 16:16:17 2008''