Biosynthesis and Functions of tRNA 2-Thiouridine in Bacillus subtilis
Cysteine desulfurases are PLP-dependent enzymes that catalyze the abstraction of sulfur from the free amino acid cysteine in a majority of organisms. Together with their sulfur acceptor proteins, these enzymes are required for the mobilization of sulfur for its incorporation into a wide variety of sulfur-containing biomolecules, including [Fe-S] clusters, thiamine, biotin and thionucleosides, such as 2-thiouridine. Thiolation of the wobble uridine on tRNA molecules to yield 2-thiouridine is critical for accuracy and efficiency in translation in all three domains of life, and depletion of this thionucleoside is associated with severe growth defects. Though its biosynthesis and functions have been well characterized in eukaryotes and Gram-negative bacteria, until now, little was known about its role or formation in Gram-positive bacteria.
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