Thioredoxin motif of Caenorhabditis elegans PDI-3 provides Cys and His catalytic residues for transglutaminase activity.
Previous reports have suggested that protein disulfide isomerases (PDIs) have transglutaminase (TGase) activity. The structural basis of this reaction has not been revealed. We demonstrate here that Caenorhabditis elegans PDI-3 can function as a Ca(2+)-dependent TGase in assays based on modification of protein- and peptide-bound glutamine residues. By site-directed mutagenesis the second cysteine residue of the -CysGlyHisCys- motif in the thioredoxin domain of the enzyme protein was found to be the active site of the transamidation reaction and chemical modification of histidine in their motif blocked TGase activity.
Blaskó
Bernadett
B
Department of Biochemistry and Molecular Biology, Faculty of Medicine, Medical and Health Science Center, University of Debrecen, POB 6, Hungary.
Mádi
András
A
Fésüs
László
L
D020816:Amino Acid Motifs; D000818:Animals; D029742:Caenorhabditis elegans Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D020134:Catalytic Domain; D003545:Cysteine / Q000235:genetics / Q000502:physiology; D005973:Glutamine / Q000378:metabolism; D006639:Histidine / Q000235:genetics / Q000502:physiology; D016297:Mutagenesis, Site-Directed; D019704:Protein Disulfide-Isomerases / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D011994:Recombinant Proteins / Q000378:metabolism; D013879:Thioredoxins / Q000737:chemistry*; D011503:Transglutaminases / Q000378:metabolism*
D029742:Caenorhabditis elegans Proteins; D011994:Recombinant Proteins; D005973:Glutamine; D006639:Histidine; D013879:Thioredoxins; D011503:Transglutaminases; D019704:Protein Disulfide-Isomerases; C472300:protein disulfide isomerase-3, C elegans; D003545:Cysteine