Substrate specificity for 4-thiouridine modification in Escherichia coli.

@article{Lauhon2004SubstrateSF,
  title={Substrate specificity for 4-thiouridine modification in Escherichia coli.},
  author={Charles T. Lauhon and Whitney M Erwin and Giangthy N Ton},
  journal={The Journal of biological chemistry},
  year={2004},
  volume={279 22},
  pages={23022-9}
}
The biosynthesis of 4-thiouridine (s4U) in Escherichia coli tRNA requires the action of both the thiamin pathway enzyme ThiI and the cysteine desulfurase IscS. IscS catalyzes sulfur transfer from l-cysteine to ThiI, which utilizes Mg-ATP to activate uridine 8 in tRNA and transfers sulfur to give s4U. In this work, we show through deletion analysis of unmodified E. coli tRNA(Phe) that the minimum substrate for s4U modification is a mini-helix comprising the stacked acceptor and T stems… CONTINUE READING