EC Number   |
Natural Substrates |
|---|
    6.1.1.27 | ATP + O-phospho-L-serine + tRNACys |
- |
| 6.1.1.27 | ATP + O-phospho-L-serine + tRNACys |
half-of-the-sites activity: the tetrameric enzyme binds two tRNAs. Only two of the four chemically equivalent subunits catalyze formation of phosphoseryl adenylate |
| 6.1.1.27 | ATP + O-phospho-L-serine + tRNACys |
Methanocaldococcus jannaschii synthesizes Cys-tRNACys by an indirect pathway, whereby O-phosphoseryltRNA synthetase (SepRS) acylates tRNACys with phosphoserine (Sep), and Sep-tRNACys-tRNA synthase (SepCysS) converts the tRNA-bound phosphoserine to cysteine |
| 6.1.1.27 | ATP + O-phospho-L-serine + tRNACys |
Methanococcus maripaludis encodes both the direct and indirect paths for Cys-tRNACys synthesis. SepS (encoding SepRS) can be deleted when the organism is grown in the presence of Cys |
| 6.1.1.27 | ATP + O-phospho-L-serine + tRNACys |
phosphoseryl-tRNA synthetase is a natural non-standard aminoacyl-tRNA synthetase, which charges a non-standard amino acid, phosphoserine, to tRNACys containing a GCA anticodon for tRNA-dependent cysteine biosynthesis in some archaea |
| 6.1.1.27 | ATP + O-phospho-L-serine + tRNACys |
some methanogenic archaea synthesize Cys-tRNACys needed for protein synthesis using both a canonical cysteinyl-tRNA synthetase as well as a set of two enzymes that operate via a separate indirect pathway. In the indirect route, Sep-tRNACys is first synthesized by SepRS, and this misacylated intermediate is then converted to Cys-tRNACys by Sep-tRNA:Cys-tRNA synthase via a pyridoxal phosphate-dependent mechanism, structural basis for the tRNACys isoacceptor preferences of SepRS and CysRS, detailed overview |
| 6.1.1.27 | ATP + O-phospho-L-serine + tRNACys |
the enzyme charges tRNACys with a 3'-deoxyadenosine, but not tRNACys without A76 or with a 2'-deoxyadensosine |
| 6.1.1.27 | more |
two-step Cys-tRNACys formation: in organisms like Archaeoglobus fulgidus lacking a canonical cysteinyl-tRNA synthetase for the direct Cys-tRNACys formation, Cys-tRNACys is produced by the indirect pathway, in which the noncanonical O-phosphoseryl-tRNA synthetase, SepRS, ligates the noncanonical amino acid O-phosphoserine, Sep, to tRNACys, and the Sep-tRNA:Cys-tRNA synthase converts the produced Sep-tRNACys to Cys-tRNACys, overview, the SepRS/SepCysS pathway is the sole route for cysteine biosynthesis in the organism |
| 6.1.1.27 | more |
two-step Cys-tRNACys formation: in organisms like Methanococcus jannaschii lacking a canonical cysteinyl-tRNA synthetase for the direct Cys-tRNACys formation, Cys-tRNACys is produced by the indirect pathway, in which the noncanonical O-phosphoseryl-tRNA synthetase, SepRS, ligates the noncanonical amino acid O-phosphoserine, Sep, to tRNACys, and the Sep-tRNA:Cys-tRNA synthase converts the produced Sep-tRNACys to Cys-tRNACys, overview, the SepRS/SepCysS pathway is the sole route for cysteine biosynthesis in the organism |
| 6.1.1.27 | more |
Methanocaldococcus jannaschii synthesizes Cys-tRNACys by an indirect pathway, whereby O-phosphoseryl-tRNA synthetase acylates tRNACys with phosphoserine, and Sep-tRNA-Cys-tRNA synthase converts the tRNA-bound phosphoserine to cysteine. Methanocaldococcus jannaschii SepRS differs from CysRS by recruiting the m1G37 modification as a determinant for aminoacylation |
