Identification of the Major Expressed S-Layer and Cell Surface-Layer-Related Proteins in the Model Methanogenic Archaea: Methanosarcina barkeri Fusaro and Methanosarcina acetivorans C2A

Figure 3

The M. acetivorans MA0829 gene locus and mRNA 5′ end. (a) The MA0829-MA0831 gene region encodes the S-layer protein (MA0829), plus two hypothetical proteins of unknown function (MA0830 and MA0831). The Genebank name (MA number) is shown above each gene. A predicted hairpin loop is indicated between MA0829 and MA0830. Intergenic distances are in nucleotides. (b) Alignment of the upstream and untranslated leader regions of genes encoding the Methanosarcina S-layer protein. The alignment of the upstream DNA sequences is relative to the start of transcription (+1 position for M. acetivorans slmA1, see text) while the ATG position of the initiation codon is indicated by the M. Numbering is relative to the transcription start. Identity of the sequences is indicated by asterisks. The putative TATA-box sequences are indicated by the bracket. The mRNA 5′ end positions for M. acetivorans and M. barkeri were determined with a ubiquitous ladder (data not shown). The six first N-terminal amino acids for the unprocessed M. acetivorans MA0829 preprotein are indicated by the single amino acid code.