Mechanistic Investigation of the Flavin-Neighboring Residues S45, A46 and I335 in Pseudomonas aeruginosa D-arginine Dehydrogenase

Pseudomonas aeruginosa ᴅ-arginine dehydrogenase (PaDADH) is a flavin-dependent enzyme. The enzyme catalyzes the oxidative deamination of a broad range of ᴅ-amino acids to their corresponding imino-acids, which are non-enzymatically hydrolyzed to α-keto-acids and ammonia. A46, S45 and I335 residues a...

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Bibliographic Details
Main Authors: Ouedraogo, Daniel, Gadda, Gioavanni
Format: Others
Published: ScholarWorks @ Georgia State University 2015
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Online Access:http://scholarworks.gsu.edu/chemistry_theses/83
http://scholarworks.gsu.edu/cgi/viewcontent.cgi?article=1083&context=chemistry_theses
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Summary:Pseudomonas aeruginosa ᴅ-arginine dehydrogenase (PaDADH) is a flavin-dependent enzyme. The enzyme catalyzes the oxidative deamination of a broad range of ᴅ-amino acids to their corresponding imino-acids, which are non-enzymatically hydrolyzed to α-keto-acids and ammonia. A46, S45 and I335 residues are located in flexible loops, which form a flask-like substrate-binding pocket. In this study, I335, A46, and S45 were mutated to histidine, glycine, and alanine, respectively and individually, through site-directed mutagenesis, to investigate their role in binding and catalysis in PaDADH. The results showed that A46 and S45 residues participate in the optimal orientation of the substrate α-amino group and I335 modulate the active site flexibility.