• The Korean Journal of Food And Nutrition
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• v.9 no.4
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• pp.452-458
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• 1996

A PPIase gene of Bacillus stearothermophilus was screened from a genomic library by plaque hybridization using the A-1 primer as a probe. A PPIase positive plaque contained a 3.0kb insert of the chromosomal DNA. A 3.0kb fragment was subcloned into pUC18, resulting pPI1-40. A DNA fragment encoding the N-terminal portion of the PPIase in pPi-40 was amplified by polymerase chain reaction(PCR) method using the A-1 and B-2 primers. The amplified fragment was cloned into the Sma I site of pUC18 and recombinant plasmid was designated as pSN-18. The nucleotide sequence of 167bp fragment was determined. The deduced amino acid sequence of PPIase was completely matched with the determined N-terminal amino acid sequence of PPIase B. stearothermophilus. The translated protein sequence of PPIase B. stearothermophilus was compared with sequence from periplasmic PPIase from Escherichina coil ; homogies of 16 and 58%, respectively, were found. The clond PPIase gene was over-expressed in E. coil cell using pUC19 as an expression vector. The enzyme was partially purified by heat treatment and colum chromatochraphy on DEAE-Sepharose CL-6B. The molecular weight of the enzyme was dermined to be about 18.0 kDal by SDS-PAGE.