| Sulfide assimilation | S188_ch_03715 | O-acetyl-L-homoserine sulfhydrylase |
| S188_ch_05019 | Homoserine O-acetyltransferase |
| S188_ch_02391; S188_ch_02939 | Cysteine synthase |
| Serine biosynthesis | S188_01905 | D-3-phosphoglycerate dehydrogenase |
| S188_ch_03473 | Phosphoserine aminotransferase |
| S188_ch_03080; S188_ch_03084 | Phosphoserine phosphatase |
| S188_ch_03845 | Putative phosphoserine phosphatase 2 |
| Cysteine biosynthesis | S188_ch_02414 | S-adenosylmethionine synthase |
| S188_ch_03749 | Homocysteine S-methyltransferase |
| S188_ch_02138 | 5’-methylthioadenosine/S-adenosylhomocysteine nucleosidase |
| S188_ch_02426 | S-ribosylhomocysteine lyase |
| S188_ch_02137 | O-acetylserine-dependent cystathionine beta-synthase |
| S188_ch_02136; S188_ch_04308 | Cystathionine gamma-lyase |
| Methionine biosynthesis | S188_ch_01671; S188_ch_02273; S188_ch_05176 | Aspartokinase |
| S188_ch_01672 | Aspartate-semialdehyde dehydrogenase |
| S188_ch_02530 | Homoserine dehydrogenase |
| S188_ch_03476 | O-acetyltransferase |
| S188_ch_02505; S188_ch_043091 | Cystathionine beta-lyase |
| S188_ch_04180 | Methionine synthase |
| Rhodanese/sulfurtransferases | S188_ch_00937 | Putative rhodanese-like domain-containing protein |
| S188_ch_02024 | Thiosulfate sulfurtransferase |
| S188_ch_02398 | Sulfurtransferase |
| S188_ch_05007 | Putative thiosulfate sulfurtransferase |
| S188_ch_05516 | Rhodanese-related sulfurtransferase |
| Nitrogen reduction | S188_ch_03676 | Nitrate reductase |