quantitative spectrophotometric assay for staphylococcal lipase.we report the development of a specific spectrophotometric assay for the quantitative determination of lipase activity in staphylococcus aureus. the assay is based on the rate of clearance of a tributyrin emulsion, and it can detect as little as 1.0 micrograms of purified pseudomonas lipase per ml. by comparison with the reaction rates obtained with pseudomonas lipase, we calculated that s. aureus ps54c and s6c produce approximately 15 and 60 micrograms of extracellular lipase per ml, respective ...19921444391
extent of the dna sequence required in integration of staphylococcal bacteriophage l54a.we characterized the minimum length of the dna sequence of the attachment sites involved in the integrative recombination of staphylococcal bacteriophage l54a. a dna fragment carrying the functional viral attachment site (attp) or the bacterial attachment site (attb) was sequentially trimmed, recloned, and tested for integrative recombination in vivo. the size of the functional attp site was at least 228 base pairs (bp) but no more than 235 bp. the left endpoint of the attp site was located to b ...19892522092
nucleotide sequence and genetic characterization of staphylococcal bacteriophage l54a int and xis genes.the nucleotide sequence of a staphylococcal bacteriophage l54a dna fragment containing genes involved in site-specific recombination was determined. mutations generated by in vitro mutagenesis were used to map and characterize the int and xis genes. the site-specific recombination functions are tightly clustered within a 1.75-kilobase stretch of dna fragment with the gene order of attp-int-xis. the int and xis genes are transcribed divergently. the int protein deduced from the nucleotide sequenc ...19892526804
lysogenic conversion of staphylococcal lipase is caused by insertion of the bacteriophage l54a genome into the lipase structural gene.staphylococcus aureus ps54 manifests no lipase (geh) activity. this is due to the insertion of bacteriophage l54a dna into the geh structural gene. the nucleotide sequence of this 2,968-base-pair dna fragment was determined. lipase deduced from the nucleotide sequence is a polypeptide of 690 amino acids which extends from nucleotide 706 to 2776.19863009394
improved single-copy integration vectors for staphylococcus aureus.we have previously reported the construction of staphylococcus aureus single-copy integration vectors based on the lysogenic bacteriophage l54a site-specific recombination system. these vectors can replicate autonomously in escherichia coli, which allows dna manipulations. in s. aureus, the vectors, which do not possess staphylococcal replication function, can only be maintained by integrating into the chromosome. however, the original vectors have limited cloning sites and do not have protectio ...200717512993
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