Molecular identification and properties of a light-insensitive rice catalase-B expressed in E. coli.
Catalase plays a central role in plant stress responses but is highly susceptible to photoinhibition. A rice catalase-B protein avoiding photoinhibition was developed by mutagenesis of specific amino acids: Leu-189 to Trp-189 and His-225 to Thr-225 and then recombinantly expressed in E. coli. In addition, the site specific mutation also induced 2-2.5-fold increase in enzyme velocity with high affinity for its substrate and showed nearly a 3-fold lower K(m) than the wild protein. These characteristic of mutated rice catalase-B is highly promising in transgenic research to increase plant productivity under stress conditions.
Mondal
Prosenjit
P
Stress Biology Laboratory, Institute of Life Sciences, Nalco Square, Chandrasekharpur, Bhubaneswar, Orissa, India.
Ray
Mamata
M
Kar
Manoranjan
M
Sabat
Surendra Ch
SCh
D002374:Catalase / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D003001:Cloning, Molecular; D004926:Escherichia coli / Q000235:genetics* / Q000378:metabolism; D017343:Genes, Plant; D007700:Kinetics; D008027:Light; D008958:Models, Molecular; D016297:Mutagenesis, Site-Directed; D012275:Oryza / Q000201:enzymology* / Q000235:genetics / Q000378:metabolism; D010957:Plasmids; D011487:Protein Conformation; D011994:Recombinant Proteins / Q000737:chemistry / Q000378:metabolism
D011994:Recombinant Proteins; D002374:Catalase