EC Number   |
Substrates |
Organism |
Products |
Reversibility |
|---|
  2.8.1.B3 | sulfurtransferase IscS-SSH + adenylated-tRNA-uridine(position8) |
- |
Escherichia coli |
sulfurtransferase IscS-SH + tRNA-4-thiouridine(position8) + AMP |
- |
ir |
| 2.8.1.B3 | sulfurtransferase IscS-SSH + adenylated-tRNA-uridine(position8) |
- |
Thermotoga maritima |
sulfurtransferase IscS-SH + tRNA-4-thiouridine(position8) + AMP |
- |
? |
| 2.8.1.B3 | sulfurtransferase IscS-SSH + adenylated-tRNA-uridine(position8) |
the biosynthesis of 4-thiouridine in Escherichia coli tRNA requires the action of both the thiamine pathway enzyme ThiI and the cysteine desulfurase IscS. IscS catalyzes sulfur transfer from L-cysteine to ThiI, which utilizes MgATP2- to activate uridine 8 in tRNA and transfers sulfur to give s4U |
Escherichia coli |
sulfurtransferase IscS-SH + tRNA-4-thiouridine(position8) + AMP |
- |
? |
| 2.8.1.B3 | sulfurtransferase IscS-SSH + adenylated-tRNA-uridine(position8) |
ThiI is a recipient of S(0) from IscS and catalyzes the ultimate sulfur transfer step in the biosynthesis of 4-thiouridine |
Escherichia coli |
sulfurtransferase IscS-SH + tRNA-4-thiouridine(position8) + AMP |
- |
? |
| 2.8.1.B3 | sulfurtransferase IscS-SSH + adenylated-tRNA-uridine(position8) |
Cys456 bears a persulfide group upon incubation with sulfurtransferase IscS and cysteine, no intermediate sulfur carrier protein is chemically required |
Escherichia coli |
sulfurtransferase IscS-SH + tRNA-4-thiouridine(position8) + AMP |
- |
? |
| 2.8.1.B3 | sulfurtransferase IscS-SSH + adenylated-tRNA-uridine(position8) |
sulfane sulfur generated by IscS is transferred sequentially to ThiI and then to tRNA during the in vitro synthesis of 4-thiouridine |
Escherichia coli |
sulfurtransferase IscS-SH + tRNA-4-thiouridine(position8) + AMP |
- |
? |
| 2.8.1.B3 | sulfurtransferase IscS-SSH + adenylated-tRNA-uridine(position8) |
the biosynthesis of 4-thiouridine 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 MgATP2- to activate uridine 8 in tRNA and transfers sulfur to give s4U. Outside of the modified uridine 8, there is no primary sequence requirement for substrate recognition. However, the secondary and tertiary structure restrictions appear sufficient to explain why s4U modification is limited in the cell to tRNA |
Escherichia coli |
sulfurtransferase IscS-SH + tRNA-4-thiouridine(position8) + AMP |
- |
? |
| 2.8.1.B3 | sulfurtransferase IscS-SSH + adenylated-tRNA-uridine(position8) |
ThiI receives the sulfur transferred from the persulfide group of the sulfurtransferase IscS. Formation of a disulfide bond between Cys-344 and Cys-456 of ThiI. Evidence for the persulfidedisulfidethiol cycle at Cys-456 of ThiI |
Escherichia coli |
sulfurtransferase IscS-SH + tRNA-4-thiouridine(position8) + AMP |
- |
? |
| 2.8.1.B3 | sulfurtransferase IscS-SSH + adenylated-tRNA-uridine(position8) |
two mechanisms for the sulfur transfer mediated by ThiI are proposed: A. mechanism providing for the direct nucleophilic attack on an activated uridine species by the terminal sulfur of the persulfide on Cys-456 of ThiI. B. mechanism in which ThiI functions to generate hydrogen sulfide, which subsequently serves as the nucleophile to displace the activated oxygen of uridine 8 |
Escherichia coli |
sulfurtransferase IscS-SH + tRNA-4-thiouridine(position8) + AMP |
- |
? |
| 2.8.1.B3 | sulfurtransferase IscS-SSH + adenylated-tRNA-uridine(position8) |
- |
Bacillus subtilis PS832 |
sulfurtransferase IscS-SH + tRNA-4-thiouridine(position8) + AMP |
- |
? |
