1oyv: Difference between revisions

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

Multidomain proteinase inhibitors play critical roles in the defense of plants against predation by a wide range of pests. Despite a wealth of structural information on proteinase-single domain inhibitor interactions, the structural basis of inhibition by multidomain proteinase inhibitors remains poorly understood. Here we report the 2.5-A resolution crystal structure of the two-headed tomato inhibitor-II (TI-II) in complex with two molecules of subtilisin Carlsberg; it reveals how a multidomain inhibitor from the Potato II family of proteinase inhibitors can bind to and simultaneously inhibit two enzyme molecules within a single ternary complex. The N terminus of TI-II initiates the folding of Domain I (Lys-1 to Cys-15 and Pro-84 to Met-123) and then completes Domain II (Ile-26 to Pro-74) before coming back to complete the rest of Domain I (Pro-84 to Met-123). The two domains of TI-II adopt a similar fold and are arranged in an extended configuration that presents two reactive site loops at the opposite ends of the inhibitor molecule. Each subtilisin molecule interacts with a reactive site loop of TI-II through the standard, canonical binding mode. Remarkably, a significant distortion of the active site of subtilisin is induced by the presence of phenylalanine in the P1 position of reactive site loop II of TI-II. The structure of the TI-II.(subtilisin)2 complex provides a molecular framework for understanding how multiple inhibitory domains in a single Potato II type proteinase inhibitor molecule from the Potato II family act to inhibit proteolytic enzymes.

1OYV is a [http://en.wikipedia.org/wiki/Protein_complex Protein complex] structure of sequences from [http://en.wikipedia.org/wiki/Bacillus_licheniformis Bacillus licheniformis] and [http://en.wikipedia.org/wiki/Solanum_lycopersicum Solanum lycopersicum] with <scene name='pdbligand=CA:'>CA</scene> as [http://en.wikipedia.org/wiki/ligand ligand]. Active as [http://en.wikipedia.org/wiki/Subtilisin Subtilisin], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.4.21.62 3.4.21.62] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1OYV OCA].  

[[Category: Barrette-Ng, I H.]]

[[Category: Cherney, M M.]]

[[Category: James, M N.]]

[[Category: Ng, K K.]]

[[Category: Ryan, C A.]]

''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 14:23:15 2008''