Expression of a pectin lyase gene in Escherichia coli from Pseudomonas marginalis N6301.

We constructed deletion mutant clones of a pectin lyase gene, and measured their pectin lyase activities in Escherichia coli. Pectin lyase activities were detected only in a recA+ strain but not in a recA- strain of E. coli. We also cloned and sequenced recA from Pseudomonas marginalis N6301. The recA from P. marginalis N6301 can complement recA- to form recA+ in the phenotype of E. coli. Highly conserved sequences of recA are observed among E. coli, P. fluorescens, and P. marginalis. From these results, we presume that recA is required for the expression of the pectin lyase gene in P. marginalis N6301.