SITE-DIRECTED MUTAGENESIS OF THE DICHL OROMETHANE DEHALOGENASE GENE FROM METHYLOPHILUS SP.STRAIN DM11
嗜甲基菌DM11菌株二氯甲烷脱卤素酶基因的定点诱变

In order to investigate the role of different residues of Methylophilus sp.strain DM11 dichloromethane dehalogenase for substrate binding, glutatione affinity,and catalytic activity, site-directed mutagenesis studies of the gene encoding the enzyme were carried ouL The conserved tryptophane residue at 103 region was respectively substituted by phenylalanine, valine or asparagine. The conserved arginine residue at 109 region was substituted by leucine. The conserved tryptophane residue at 117 region was respectively substituted by tyrosine or phenylaleine. Six mutant enzymes were propuced. Among them three possess lower activities, other three do not possess activity. The properties of the mutant enzyme W117Y are very different from wild-type enzyme.