tailieunhanh - Báo cáo khoa học: Carboxylate and aromatic active-site residues are determinants of high-affinity binding of x-aminoaldehydes to plant aminoaldehyde dehydrogenases

The crystal structures of both isoforms of the aminoaldehyde dehydroge-nase from pea (PsAMADH) have been solved recently [Tylichova´ et al. (2010) J Mol Biol396, 870–882]. The characterization of the PsAMADH2 proteins, altered here by site-directed mutagenesis | IFEBS Journal Carboxylate and aromatic active-site residues are determinants of high-affinity binding of x-aminoaldehydes to plant aminoaldehyde dehydrogenases I-S I IX v -I- I I r 1 I rt í-í-2 I I II 3 inn A 1 David Kopecin Martina Tylichova Jacques Snegaroff Hana Popelkova and Marek Sebela 1 Department of Protein Biochemistry and Proteomics Centre of the Region Hanci for Biotechnologicaland AgriculturalResearch Faculty of Science Palacky University Olomouc Czech Republic 2 Institut Jean-Pierre Bourgin UMR1318 INRA-AgroParisTech Versailles Cedex France 3 Department of Molecular Cellular and DevelopmentalBiology University of Michigan Ann Arbor MI USA Keywords 3- aminopropionaldehyde 4- aminobutyraldehyde 4-guanidinobutyraldehyde aminoaldehyde dehydrogenase betaine aldehyde Correspondence D. Kopecny M. Sebela Department of Protein Biochemistry and Proteomics Center of the Region Hana for Biotechnologicaland AgriculturalResearch Faculty of Science Palacky University ỗlechtitelủ 11 CZ-783 71 Olomouc Czech Republic Fax 420 585634933 Tel 420 585634927 E-mail kopecny_david@ Received 23 May 2011 revised 7 June 2011 accepted 6 July 2011 doi The crystal structures of both isoforms of the aminoaldehyde dehydrogenase from pea PsAMADH have been solved recently Tylichova et al. 2010 J Mol Biol 396 870-882 . The characterization of the PsAMADH2 proteins altered here by site-directed mutagenesis suggests that the D110 and D113 residues at the entrance to the substrate channel are required for high-affinity binding of ro-aminoaldehydes to PsAMADH2 and for enzyme activity whereas N162 near catalytic C294 contributes mainly to the enzyme s catalytic rate. Inside the substrate cavity W170 and Y163 and to a certain extent L166 and M167 probably preserve the optimal overall geometry of the substrate channel that allows for the appropriate orientation of the substrate. Unconserved W288 appears to affect the affinity