FIG 1.

Hvo_0405 is a fusion protein resulting from a single base deletion. (A) Predicted amino acid sequence alignment of Hvo_0405 with sequences of two proteins in other Haloferax species, which are encoded by genes adjacent to each other. Proteins homologous to the N-terminal region of Hvo_0405 contain a predicted Tat signal peptide, a signal peptidase I (SPase I)-processing site (arrowhead), conserved LVIVD repeat domains, and a PGF motif followed by a hydrophobic stretch and a positively charged region typical of ArtA substrates. Proteins homologous to the Hvo_0405 C-terminal region contain a NifU-like domain. An asterisk indicates positions which have a single, fully conserved residue, a colon indicates conservation between groups with strongly similar properties, and a period indicates conservation between groups with weakly similar properties. (B) Nucleotide alignment of the DNA sequences homologous to hvo_0405; the H. volcanii hvo_0405 gene appears to have lost a conserved cytosine 1,462 bp 3′ of the start site. This single-base-pair deletion (arrow) results in a frameshift, replacing the last five amino acids, eliminating the stop codon, and resulting in an in-frame intergenic region leading to the fusion that includes the N- and C-terminal regions of Hvo_0405. The protein and DNA sequence alignments shown include sequences from four Haloferax species, in addition to H. volcanii, which are representative of the sequences tested for all 11 Haloferax genomes available to date.