1tec: Difference between revisions

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

In order to investigate the principles of protein thermostability, the crystal structure of thermitase from Thermoactinomyces vulgaris, a thermostable member of the subtilisin family of serine proteases, has been determined in a complex with eglin c. Eglin c is a serine protease inhibitor from the leech Hirudo medicinalis. After data collection with a television area-detector diffractometer and initial structure solution by molecular-replacement methods, crystallographic refinement proceeded with incorporation of molecular-dynamics techniques. It appeared that this refinement procedure has a large convergence radius with movements of more than 5 A for many atoms. Two procedures for the crystallographic molecular-dynamics refinement have been tested. They differed mainly in time span and weight on the X-ray 'energy'. The best results were obtained with a procedure which allowed the molecular-dynamics technique to search a large area in conformational space by having less weight on the X-ray restraints and allowing more time. The use of molecular-dynamics refinement considerably simplified the laborious and difficult task of fitting the model in its electron density during the refinement process. The final crystallographic R factor is 17.9% at 2.2 A resolution.

1TEC is a [http://en.wikipedia.org/wiki/Protein_complex Protein complex] structure of sequences from [http://en.wikipedia.org/wiki/Hirudo_medicinalis Hirudo medicinalis] and [http://en.wikipedia.org/wiki/Thermoactinomyces_vulgaris Thermoactinomyces vulgaris] with <scene name='pdbligand=CA:'>CA</scene> and <scene name='pdbligand=NA:'>NA</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Thermitase Thermitase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.4.21.66 3.4.21.66] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1TEC OCA].  

[[Category: Dijkstra, B W.]]

[[Category: Hol, W G.J.]]

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