2006/07/19 by John E. Dominy, Chad R. Simmons, C.R. Simmons +3 · 109 citations
Agricultural and Biological Sciences · Biochemistry, Genetics and Molecular Biology · Chemistry · #Amino acid #Bacillus subtilis #Bacteria #Biochemistry #Biology #Cassava research and cyanide #Cysteine #Cysteine metabolism #Enzyme #Gene #Genetics #Metal-Catalyzed Oxygenation Mechanisms #Mutant #Peroxisome Proliferator-Activated Receptors #Streptomyces coelicolor
paper · open access · doi:10.1128/jb.00291-06
published in Journal of Bacteriology 188(15), 5561-5569 (American Society for Microbiology)
openalex publication_date 2006/07/19 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/01
In metazoa and fungi, the catabolic dissimilation of cysteine begins with its sulfoxidation to cysteine sulfinic acid by the enzyme cysteine dioxygenase (CDO). In these organisms, CDO plays an important role in the homeostatic regulation of steady-state cysteine levels and provides important oxidized metabolites of cysteine such as sulfate and taurine. To date, there has been no experimental evidence for the presence of CDO in prokaryotes. Using PSI-BLAST searches and crystallographic information about the active-site geometry of mammalian CDOs, we identified a total of four proteins from Bacillus subtilis, Bacillus cereus, and Streptomyces coelicolor A3(2) that shared low overall identity to CDO (13 to 21%) but nevertheless conserved important active-site residues. These four proteins were heterologously expressed and purified to homogeneity by a single-step immobilized metal affinity chromatography procedure. The ability of these proteins to oxidize cysteine to cysteine sulfinic acid was then compared against recombinant rat CDO. The kinetic data strongly indicate that these proteins are indeed bona fide CDOs. Phylogenetic analyses of putative bacterial CDO homologs also indicate that CDO is distributed among species within the phyla of Actinobacteria, Firmicutes, and Proteobacteria. Collectively, these data suggest that a large subset of eubacteria is capable of cysteine sulfoxidation. Suggestions are made for how this novel pathway of cysteine metabolism may play a role in the life cycle of the eubacteria that have it.