Arrangement and expression of methyl com reductase genes in Methanococcus voltae

Abstract

Summary The structural genes coding for component C of methyl CoM reductase of Methanococcus voltae were identified after shotgun cloning of Methanococcus voltae DNA in an Escherichia coli expression plasmid and subsequent screening with antibodies against the enzyme subunits, α, β and γ. Further analysis using bacteriophage ψ vectors with Methanococcus voltae DNA inserts from a genomic library and Southern blot analysis of Methanococcus voltae genomic DNA fragments served to localize the genes on specific restriction fragments and to establish a physical map. The three genes are adjacent to one another in the order β-γ-α. S1 mapping and the analysis of the ψ-α-intergenic region shows that at least these two genes are transcribed into a polycistronic message. Transcription termination signals — located in a typical AT-rich region — were identified. A strong ribosome binding site is located in the intergenic region in front of the α-gene. Sequence analysis yielded strikingly similar codon usage in two genes.