Activities | Families | Sequences | Fold types | References | Help
B6db activities: 2.5.1.73

2.5.1.73
Description O-phospho-L-seryl-tRNA:Cys-tRNA synthase
Catalyzed reaction O-phospho-L-seryl-tRNACys + sulfide = L-cysteinyl-tRNACys + phosphate
Cofactor Pyridoxal phosphate
Comments
In organisms like Archaeoglobus fulgidus lacking EC 6.1.1.16 for the direct Cys-tRNA(Cys) formation, Cys-tRNA(Cys) is produced by an indirect pathway, in which EC 6.1.1.27 ligates O-phosphoserine to tRNA(Cys), and EC 2.5.1.73 converts the produced O-phospho-L-seryl- tRNA(Cys) to Cys-tRNA(Cys).
The SepRS/SepCysS pathway is the sole route for cysteine biosynthesis in the organism.
Methanosarcina mazei can use both pathways, the direct route using EC 6.1.1.16 and the indirect pathway with EC 6.1.1.27 and EC 2.5.1.73.
Formerly EC 2.5.1.n3.
The translation of cysteine codons in mRNA during protein synthesis requires cysteinyltRNA (Cys-tRNACys). Cys-tRNACys is normally synthesized from the amino acid cysteine and the corresponding tRNA isoacceptors (tRNACys) in an adenosine triphosphate (ATP)– dependent reaction catalyzed by cysteinyltRNA synthetase (CysRS). The proteomes of a number of methanogenic archaea either lack CysRS, Sep-tRNACys is then converted to Cys-tRNACys by SepCysS in these methanogenic archea.
PDB 3WKR;
Organisms -Archea
 

Family 

2.5.1.73 (0)
 
Links Enzyme (activities) 2.5.1.73
BRENDA (activities) 2.5.1.73
KEGG (pathways) 2.5.1.73
PLPMDB (PLP mutants) 2.5.1.73
 
References
 Sauerwald A, Zhu W, Major TA, Roy H, Palioura S, Jahn D, Whitman WB, Yates JR rd, Ibba M, Söll D. (2005) RNA-dependent cysteine biosynthesis in archaea. Science 307 1969-72.

Articles on 2.5.1.73
 
last changed 2018/03/23 14:41

B6db activities