2iaa
Crystal Structure of an Electron Transfer Complex Between Aromatic Amine Dephydrogenase and Azurin from Alcaligenes Faecalis (Form 2)
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OverviewOverview
The crystal structure of an electron transfer complex of aromatic amine, dehydrogenase (AADH) and azurin is presented. Electrons are transferred, from the tryptophan tryptophylquinone (TTQ) cofactor of AADH to the type I, copper of the cupredoxin azurin. This structure is compared with the, complex of the TTQ-containing methylamine dehydrogenase (MADH) and the, cupredoxin amicyanin. Despite significant similarities between the two, quinoproteins and the two cupredoxins, each is specific for its respective, partner and the ionic strength dependence and magnitude of the binding, constant for each complex are quite different. The AADH-azurin interface, is largely hydrophobic, covering approximately 500 A(2) of surface on each, molecule, with one direct hydrogen bond linking them. The closest distance, from TTQ to copper is 12.6 A compared with a distance of 9.3 A in the, MADH-amicyanin complex. When the MADH-amicyanin complex is aligned with, the AADH-azurin complex, the amicyanin lies on top of the azurin but is, oriented quite differently. Although the copper atoms differ in position, by approximately 4.7 A, the amicyanin bound to MADH appears to be rotated, approximately 90 degrees from its aligned position with azurin. Comparison, of the structures of the two complexes identifies features of the, interface that dictate the specificity of the protein-protein interaction, and determine the rate of interprotein electron transfer.
About this StructureAbout this Structure
2IAA is a Single protein structure of sequence from Alcaligenes faecalis with CU as ligand. Active as Aralkylamine dehydrogenase, with EC number 1.4.99.4 Full crystallographic information is available from OCA.
ReferenceReference
Crystal structure of an electron transfer complex between aromatic amine dehydrogenase and azurin from Alcaligenes faecalis., Sukumar N, Chen ZW, Ferrari D, Merli A, Rossi GL, Bellamy HD, Chistoserdov A, Davidson VL, Mathews FS, Biochemistry. 2006 Nov 14;45(45):13500-10. PMID:17087503
Page seeded by OCA on Wed Nov 21 12:12:36 2007