Role of H164 in a unique dye-decolorizing heme peroxidase DyP.
The expression system of a unique dye-decolorizing peroxidase DyP in Escherichia coli has been constructed. The molecular mass of the expressed DyP (eDyP) is 47kDa, indicating no any modification with saccharides. The characteristics of eDyP were almost the same as those of native DyP from a fungus Thanatephorus cucumeris Dec 1 and recombinant DyP with Aspergillus oryzae except thermostability. As H164 was suggested to be the proximal histidine based on the preliminary X-ray crystallographic analysis of DyP, the site-directed mutations H164A and H166A (residue near H164) were introduced into the gene encoding DyP. The specific activity and RZ value of the purified H164A were 1.52U/mg and 0.11, respectively, which were 99.8% and 95% lower than those of eDyP, respectively. On the contrary, those of H166A were not different from those of eDyP. Therefore, H164 was confirmed to be the proximal histidine.
Chemical Resources Laboratory, Tokyo Institute of Technology, R1-29-4259 Nagatsuta, Midori-ku, Yokohama 226-8503, Japan.
Yasushi
Y
Sugano
Yosuke
Y
Ishii
Makoto
M
Shoda
D019943:Amino Acid Substitution; D001391:Azo Compounds / Q000737:chemistry; D004396:Coloring Agents / Q000737:chemistry*; D004789:Enzyme Activation; D004795:Enzyme Stability; D004926:Escherichia coli / Q000201:enzymology* / Q000235:genetics; D006418:Heme / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D008970:Molecular Weight; D010544:Peroxidases / Q000737:chemistry*; D015202:Protein Engineering / Q000379:methods*; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000737:chemistry; D013329:Structure-Activity Relationship; D013379:Substrate Specificity
D001391:Azo Compounds; D004396:Coloring Agents; D011994:Recombinant Proteins; D006418:Heme; D010544:Peroxidases