The metH gene from Salmonella typhimurium LT2: cloning and initial characterization.

A 19-kb EcoRI DNA fragment carrying the metH gene of Salmonella typhimurium LT2 was cloned into plasmid vector pACYC184 and propagated in Escherichia coli K-12. The size of the metH gene product was observed to be approx. 120 kDa, as determined by SDS-polyacrylamide gel analysis of plasmid-specific polypeptides synthesized in a minicell system. The direction of transcription of the metH gene relative to the cloned fragment was determined, and the positions of translation initiation and termination were estimated.