1qs0: Difference between revisions

[[Image:1qs0.jpg|left|200px]]<br /><applet load="1qs0" size="350" color="white" frame="true" align="right" spinBox="true"  

The family of giant multienzyme complexes metabolizing pyruvate, 2-oxoglutarate, branched-chain 2-oxo acids or acetoin contains several of the largest and most sophisticated protein assemblies known, with molecular masses between 4 and 10 million Da. The principal enzyme components, E1, E2 and E3, are present in numerous copies and utilize multiple cofactors to catalyze a directed sequence of reactions via substrate channeling. The crystal structure of a heterotetrameric (alpha2beta2) E1, 2-oxoisovalerate dehydrogenase from Pseudomonas putida, reveals a tightly packed arrangement of the four subunits with the beta2-dimer held between the jaws of a 'vise' formed by the alpha2-dimer. A long hydrophobic channel, suitable to accommodate the E2 lipoyl-lysine arm, leads to the active site, which contains the cofactor thiamin diphosphate (ThDP) and an inhibitor-derived covalent modification of a histidine side chain. The E1 structure, together with previous structural information on E2 and E3, completes the picture of the shared architectural features of these enormous macromolecular assemblies.

1QS0 is a [http://en.wikipedia.org/wiki/Protein_complex Protein complex] structure of sequences from [http://en.wikipedia.org/wiki/Pseudomonas_putida Pseudomonas putida] with <scene name='pdbligand=MG:'>MG</scene>, <scene name='pdbligand=COI:'>COI</scene> and <scene name='pdbligand=TDP:'>TDP</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1QS0 OCA].  

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

[[Category: Sokatch, J R.]]

''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 14:43:05 2008''