FIG. 4.

Lysine biosynthetic pathways. Enzymes: 1, aspartate kinase; 2, aspartate semialdehyde dehydrogenase; 3, dihydrodipicolinate synthase; 4, dihydrodipicolinate reductase; 5, tetrahydropicolinate succinylase; 6, succinyldiaminopimelate transaminase; 7, succinyldiaminopimelate desuccinylase; 8, diaminopimarate epimerase; 9, diaminopimelate decarboxylase; 10, homocitrate synthase; 11, homoaconitate hydratase; 12, homoisocitrate dehydrogenase; 13, 2-aminoadipate transaminase; 14, l-aminoadipate semialdehyde dehydrogenase; 15, saccharopine dehydrogenase (NADP⁺, l-glutamate forming); 16, saccharopine dehydrogenase (NAD⁺, l-lysine forming).