MUTANT E.COLI RIBONUCLEASE H

摘要

PURPOSE:To produce mutant E.coli ribonuclease H, by forming a vector containing a mutant E.coli ribonuclease H structural gene having an amino acid sequence characterized in that the 13th cysteine is substituted with serine. CONSTITUTION:E.coli JM109/pDR601 is transformed with a manifestation vector containing a mutant E.coli ribonuclease H structural gene wherein 13th TGT codon of cysteine is converted to TCT codon of serine by site-specific mutation under the control with tac promoter. The obtained transformant is cultured under a condition suitable for the manifestation of ribonuclease H gene and the mutant E.coli ribonuclease is recovered from the resultant culture liquid to obtain the objective mutant E.coli ribonuclease H.