The gene encoding a novel bacteriorhodopsin (bR)-like protein from Haloarcula japonica strain TR-1 was cloned and sequenced. The nucleotide sequence of the gene contained an open reading frame that corresponded to a protein of 250 amino acids. The deduced amino acid sequence of Ha. japonica bR-like protein exhibited the highest homology to those of cruxrhodopsins (cRs) produced by members of the genus Haloarcula, suggesting that the bR-like protein of Ha. japonica belonged to the cR subfamily. The hydropathy analysis of Ha. japonica bR-like protein (cR) revealed that the Ha. japonica cR had a transmembrane heptahelical structure similar to that of bR. Furthermore, transcription of the cR gene in Ha. japonica was confirmed by the reverse transcription-polymerase chain reaction method.