Heterologous expression and functional characterization of cysteamine dioxygenase from the deep-sea mussel Bathymodiolus septemdierum

Abstract In invertebrates inhabiting hydrothermal vent areas, hypotaurine, a precursor of taurine, is thought to mitigate the toxicity hydrogen sulfide in fluids. Information about hypotaurine synthesis pathways limited, although two pathways, cysteamine [2-aminoethanethiol (AET)] pathway and cysteine sulfinate (CSA) are known mammals. this study, we cloned cDNA encoding AET dioxygenase (ADO), central enzyme pathway, from mussel Bathymodiolus septemdierum . encoded protein ( Bs ADO), functionally important residues, including metal-binding histidines, conserved. maximum likelihood phylogenetic analysis, ADO clustered with ADOs other invertebrates. By reverse transcription PCR, BsADO mRNA was detected all tissues examined at similar levels, suggesting that its function distinct CSA predominantly expressed gill. His tag, Escherichia coli presence Fe 2+ , converted but absence iron exhibited lower activity. active pH 8 11, 0 °C 37 °C, peak 20 °C. This first functional characterization marine