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CENTRAL CARBON → ASPARTATE FAMILY / SUCCINYL-DAP ROUTE → INDIVIDUAL PATHWAY

Lysine biosynthesis

Follow the carbon skeleton from L-Aspartate to L-Lysine.

What it needs

Aspartate, pyruvate, ATP, reducing equivalents, succinyl-CoA and nitrogen donors.

What it supplies

L-Lysine. This product can enter downstream cellular reactions; its synthesis depends on the precursor and helper supplies shown.

The pathway

Read from top to bottom. Select an enzyme box to jump to its reaction. Cosubstrates and selected coproducts appear in the account below.

Lysine biosynthesisL-Aspartate to L-Aspartyl-4-phosphate via Aspartate kinase; L-Aspartyl-4-phosphate to L-Aspartate-4-semialdehyde via Aspartate-semialdehyde dehydrogenase; Aspartate semialdehyde + pyruvate to 4-Hydroxy-tetrahydrodipicolinate via Dihydrodipicolinate synthase (DapA); 4-Hydroxy-tetrahydrodipicolinate to Tetrahydrodipicolinate via Dihydrodipicolinate reductase (DapB); Tetrahydrodipicolinate to N-Succinyl-2-amino-6-oxopimelate via Tetrahydrodipicolinate N-succinyltransferase (DapD); N-Succinyl-2-amino-6-oxopimelate to N-Succinyl-LL-diaminopimelate via Succinyl-diaminopimelate aminotransferase (DapC); N-Succinyl-LL-diaminopimelate to LL-Diaminopimelate via Succinyl-diaminopimelate desuccinylase (DapE); LL-Diaminopimelate to meso-Diaminopimelate via Diaminopimelate epimerase (DapF); meso-Diaminopimelate to L-Lysine via Diaminopimelate decarboxylase (LysA)L-Aspartate1. Aspartate kinaseATP → ADPRead reaction 1L-Aspartyl-4-phosphate2. Aspartate-semialdehyde dehydrogenaseNADPH → NADP⁺Read reaction 2L-Aspartate-4-semialdehyde3. Dihydrodipicolinate synthase (DapA)Read reaction 34-Hydroxy-tetrahydrodipicolinate4. Dihydrodipicolinate reductase (DapB)NAD(P)H supplies reducing powerRead reaction 4Tetrahydrodipicolinate5. Tetrahydrodipicolinate N-succinyltransferase (DapD)Succinyl-CoA supplies succinyl groupRead reaction 5N-Succinyl-2-amino-6-oxopimelate6. Succinyl-diaminopimelate aminotransferase (DapC)Glutamate supplies nitrogenRead reaction 6N-Succinyl-LL-diaminopimelate7. Succinyl-diaminopimelate desuccinylase (DapE)Read reaction 7LL-Diaminopimelate8. Diaminopimelate epimerase (DapF)Read reaction 8meso-Diaminopimelate9. Diaminopimelate decarboxylase (LysA)CO₂ releasedRead reaction 9L-Lysine

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Reactions and enzymes

1 · Aspartate kinase

L-Aspartate → L-Aspartyl-4-phosphate

Aspartate kinase · EC 2.7.2.4

Inputs, helpers or coproducts: ATP → ADP

2 · Aspartate-semialdehyde dehydrogenase

L-Aspartyl-4-phosphate → L-Aspartate-4-semialdehyde

Aspartate-semialdehyde dehydrogenase · EC 1.2.1.11

Inputs, helpers or coproducts: NADPH → NADP⁺

3 · Dihydrodipicolinate synthase (DapA)

Aspartate semialdehyde + pyruvate → 4-Hydroxy-tetrahydrodipicolinate

Dihydrodipicolinate synthase (DapA) · EC 4.3.3.7

4 · Dihydrodipicolinate reductase (DapB)

4-Hydroxy-tetrahydrodipicolinate → Tetrahydrodipicolinate

Dihydrodipicolinate reductase (DapB) · EC 1.17.1.8

Inputs, helpers or coproducts: NAD(P)H supplies reducing power

5 · Tetrahydrodipicolinate N-succinyltransferase (DapD)

Tetrahydrodipicolinate → N-Succinyl-2-amino-6-oxopimelate

Tetrahydrodipicolinate N-succinyltransferase (DapD) · EC 2.3.1.117

Inputs, helpers or coproducts: Succinyl-CoA supplies succinyl group

6 · Succinyl-diaminopimelate aminotransferase (DapC)

N-Succinyl-2-amino-6-oxopimelate → N-Succinyl-LL-diaminopimelate

Succinyl-diaminopimelate aminotransferase (DapC) · EC 2.6.1.17

Inputs, helpers or coproducts: Glutamate supplies nitrogen

7 · Succinyl-diaminopimelate desuccinylase (DapE)

N-Succinyl-LL-diaminopimelate → LL-Diaminopimelate

Succinyl-diaminopimelate desuccinylase (DapE) · EC 3.5.1.18

8 · Diaminopimelate epimerase (DapF)

LL-Diaminopimelate → meso-Diaminopimelate

Diaminopimelate epimerase (DapF) · EC 5.1.1.7

9 · Diaminopimelate decarboxylase (LysA)

meso-Diaminopimelate → L-Lysine

Diaminopimelate decarboxylase (LysA) · EC 4.1.1.20

Inputs, helpers or coproducts: CO₂ released

Connected pathways

Evidence and scope

This is the succinyl-DAP option. Acetyl-DAP, DAP dehydrogenase, aminotransferase and aminoadipate routes differ; this page does not assign one universal lysine route. This page explains selected documented biochemical reactions. It does not establish that every displayed enzyme occurs in Aquifex, that the pathway is universally essential, or that the book image records a complete organism. Gene symbols name common enzyme activities; organism-specific protein records require separate matching.

Original explanatory diagram and reaction account, based on the records below. Arrows show the biosynthetic reading direction; they do not claim that every reaction is irreversible. Selected protons, water and cofactors are omitted from the overview and are not implied absent.

Compare the related Aquifex annotation group →