1kuf: Difference between revisions

[[Image:1kuf.gif|left|200px]]<br /><applet load="1kuf" size="350" color="white" frame="true" align="right" spinBox="true"  

The crystal structure of TM-3, a small snake-venom metalloproteinase (SVMP) isolated from Taiwan habu (Trimeresurus mucrosquamatus), was determined at 1.35 A resolution with resultant R and R(free) values of 0.181 and 0.204, respectively. The overall structure of TM-3 is an oblate ellipsoid that contains three disulfide crosslinks, Cys118-Cys197, Cys159-Cys181 and Cys161-Cys164. It exhibits the typical structural features of SVMPs and is closely related to the structure of the catalytic proteinase domain of TNFalpha-converting enzyme (TACE). In the present structure, the essential catalytic zinc ion was found to be replaced by a cadmium ion during crystallization, as revealed by atomic absorption analysis and X-ray data. This cadmium ion is bound to six ligands, including three conserved histidines and three water molecules, displaying the coordination geometry of a distorted octahedron. One of the water molecules is proposed to play the role of stabilizing the tetrahedral intermediate during the catalysis of SVMPs. The putative S'(1) specificity pocket of TM-3 is relatively shallow, in contrast to the deep pockets of adamalysin II, atrolysin C and H(2)-proteinase, but is similar to those in acutolysin A and TACE. The shallow pocket is a consequence of the presence of the non-conserved disulfide bond Cys159-Cys181 and the residue Gln174 at the bottom of the S'(1) pocket. The results indicate that the active-site structure of TM-3, among the know structures of SVMPs examined thus far, is most similar to that of TACE owing to their close disulfide configurations and the S'(1) specificity pocket.

1KUF is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Protobothrops_mucrosquamatus Protobothrops mucrosquamatus] with <scene name='pdbligand=CD:'>CD</scene> as [http://en.wikipedia.org/wiki/ligand ligand]. Active as [http://en.wikipedia.org/wiki/Atrolysin_E Atrolysin E], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.4.24.44 3.4.24.44] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1KUF OCA].  

[[Category: Chiou, S H.]]

[[Category: Huang, K F.]]

[[Category: Ko, T P.]]

[[Category: Wang, A H.J.]]

[[Category: Yuann, J M.]]

''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 13:38:00 2008''