1fdp: Difference between revisions

The crystal structure of profactor D, determined at 2.1 A resolution with, an Rfree and an R-factor of 25.1 and 20.4%, respectively, displays highly, flexible or disordered conformation for five regions: N-22, 71-76, 143-152, 187-193 and 215-223. A comparison with the structure of its, mature serine protease, complement factor D, revealed major conformational, changes in the similar regions. Comparisons with the zymogen-active enzyme, pairs of chymotrypsinogen, trypsinogen and prethrombin-2 showed a similar, distribution of the flexible regions. However, profactor D is the most, flexible of the four, and its mature enzyme displays inactive, self-inhibited active site conformation. Examination of the surface, properties of the N-terminus-binding pocket indicates that Ile16 may play, the initial positioning role for the N-terminus, and Leu17 probably also, helps in inducing the required conformational changes. This process, perhaps shared by most chymotrypsinogen-like zymogens, is followed by a, factor D-unique step, the re-orientation of an external Arg218 to an, internal position for salt-bridging with Asp189, leading to the generation, of the self-inhibited factor D.

1FDP is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens]. Active as [http://en.wikipedia.org/wiki/Complement_factor_D Complement factor D], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.4.21.46 3.4.21.46] Structure known Active Sites: TRA, TRB, TRC and TRD. Full crystallographic information is available from [http://ispc.weizmann.ac.il/oca-bin/ocashort?id=1FDP OCA].  

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