In vivo transcripts of the S-layer-encoding structural gene of the archaeon Methanococcus voltae

The 5′ region of the S-layer-encoding structural gene (sla) of Methanococcus voltae was sequenced. The sequence information was then used to identify the in vivo transcription products of the gene. We observed three transcripts, and upstream from each transcription start point was a region with similarity to the Box A consensus sequence observed in archaeal promoters. In two of the three cases, two Box A sequences were present in tandem. This arrangement may play a role in the high level of gene expression expected for the sla gene. Presumptive archaeal Box B signatures were also identified.