| IPR003759 | Cobalamin (vitamin B12)-binding module, cap domain | Domain |
| IPR011005 | Dihydropteroate synthase-like superfamily | Homologous Superfamily |
| IPR033706 | Methionine synthase, B12-binding domain | Domain |
| IPR006158 | Cobalamin (vitamin B12)-binding domain | Domain |
| IPR003726 | Homocysteine-binding domain | Domain |
| IPR004223 | Vitamin B12-dependent methionine synthase, activation domain | Domain |
| IPR036589 | Homocysteine-binding domain superfamily | Homologous Superfamily |
| IPR000489 | Pterin-binding domain | Domain |
| IPR036724 | Cobalamin-binding domain superfamily | Homologous Superfamily |
| IPR011822 | Cobalamin-dependent methionine synthase | Family |
| IPR036594 | Methionine synthase domain | Homologous Superfamily |
| IPR037010 | Vitamin B12-dependent methionine synthase, activation domain superfamily | Homologous Superfamily |