ID 2.5.1.73 DE O-phospho-L-seryl-tRNA:Cys-tRNA synthase. AN SepCysS. AN Sep-tRNA:Cys-tRNA synthase. CA H(+) + hydrogen sulfide + O-phospho-L-seryl-tRNA(Cys) = L-cysteinyl- CA tRNA(Cys) + phosphate. CC -!- In organisms like Archaeoglobus fulgidus lacking EC 6.1.1.16 for the CC direct Cys-tRNA(Cys) formation, Cys-tRNA(Cys) is produced by an CC indirect pathway, in which EC 6.1.1.27 ligates O-phosphoserine to CC tRNA(Cys), and EC 2.5.1.73 converts the produced O-phospho-L-seryl- CC tRNA(Cys) to Cys-tRNA(Cys). CC -!- The SepRS/SepCysS pathway is the sole route for cysteine biosynthesis CC in the organism. CC -!- Methanosarcina mazei can use both pathways, the direct route using CC EC 6.1.1.16 and the indirect pathway with EC 6.1.1.27 and CC EC 2.5.1.73. CC -!- Formerly EC 2.5.1.n3. DR O30207, SPSS1_ARCFU; Q0W2L3, SPSS1_METAR; A7I757, SPSS1_METB6; DR Q12XS4, SPSS1_METBU; Q2FLN5, SPSS1_METHJ; A2SQB8, SPSS1_METLZ; DR O30056, SPSS2_ARCFU; Q0W486, SPSS2_METAR; A7I9Z8, SPSS2_METB6; DR Q12W26, SPSS2_METBU; Q2FTY4, SPSS2_METHJ; A2SSS7, SPSS2_METLZ; DR A6UUU3, SPSS_META3 ; Q8TSS3, SPSS_METAC ; Q46C09, SPSS_METBF ; DR Q59072, SPSS_METJA ; Q8TYR3, SPSS_METKA ; A4FWT8, SPSS_METM5 ; DR A9AA73, SPSS_METM6 ; A6VGH9, SPSS_METM7 ; Q8PVS9, SPSS_METMA ; DR A3CVZ3, SPSS_METMJ ; Q6LXV6, SPSS_METMP ; O27139, SPSS_METTH ; DR A0B5D0, SPSS_METTP ; A6UPN9, SPSS_METVS ; //