Expression in Escherichia coli and Pseudomonas aeruginosa of Methylophilus methylotrophus AS1 genes carried on prime plasmids

Prime plasmids carrying chromosomal fragments of Methylophilus methylotrophus AS1 were transferred to Pseudomonas aeruginosa and Escherichia coli auxotrophs. It was shown that with argF (ornithine transcarbamylase), pyrB (aspartate transcarbamylase) and trpB (tryptophan synthetase, β‐subunit) mutants of E. coli and P. aeruginosa complementation was accompanied by the synthesis of the corresponding M. methylotrophus gene product. These results support the basis of complementation mapping by prime plasmids previously used for M. methylotrophus. The level of expression of the M. methylotrophus genes varied in the two hosts but the regulation of the M. methylotrophus genes under these conditions was less responsive to cultural conditions than their expression in M. methylotrophus.