Physical mapping of genes coding for two subunits of methyl CoM reductase component C of Methanococcus voltae

Abstract

A genomic library of EcoRI*-digested cellular DNA from Methanococcus voltae was constructed in an expression vector, which allows the induction of fusion proteins of the Mc. voltae gene products with an MS2 RNA polymerase N-terminal fragment. Antibodies were raised against the subunits of the methyl CoM reductase component C complex. They were used to screen clones from the genomic library for the synthesis of polypeptides carrying antigenic determinants of the reductase subunits. Plasmids containing fragments of two of the three subunit genes were isolated. The genes were shown to be adjacent to each other by hybridization against restriction fragments of cellular DNA and Mc. voltae DNA cloned in a bacteriophage lambda replacement vector. The direction of the transcription of one of the genes was established by partial sequence determination and it was shown that the two genes have a common transcript.