Cloning and expression of a Porphyromonas (Bacteroides) gingivalis protease gene in Escherichia coli.

A genomic library of Bacteroides gingivalis W83 chromosomal DNA was constructed in the Escherichia coli lambda (lambda) vector EMBL 4. Three recombinant lambda phages expressing a cloned protease were identified in the library. All three lambda phages contained cloned overlapping DNA fragments from the same region of the chromosome and encoded the same cloned protease. The cloned protease was expressed poorly using its own promoter in E. coli.