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CENTRAL CARBON → GLUTAMATE FAMILY → INDIVIDUAL PATHWAY

Proline biosynthesis

Follow the carbon skeleton from L-Glutamate to L-Proline.

What it needs

Glutamate, ATP and reducing equivalents.

What it supplies

L-Proline. 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.

Proline biosynthesisL-Glutamate to L-Glutamate-5-phosphate via Glutamate 5-kinase (ProB); L-Glutamate-5-phosphate to L-Glutamate-5-semialdehyde via Glutamate-5-semialdehyde dehydrogenase (ProA); L-Glutamate-5-semialdehyde to Δ¹-Pyrroline-5-carboxylate via Spontaneous cyclization; Δ¹-Pyrroline-5-carboxylate to L-Proline via Pyrroline-5-carboxylate reductase (ProC)L-Glutamate1. Glutamate 5-kinase (ProB)ATP → ADPRead reaction 1L-Glutamate-5-phosphate2. Glutamate-5-semialdehyde dehydrogenase (ProA)NADPH supplies reducing powerRead reaction 2L-Glutamate-5-semialdehyde3. Spontaneous cyclizationWater releasedRead reaction 3Δ¹-Pyrroline-5-carboxylate4. Pyrroline-5-carboxylate reductase (ProC)NAD(P)H supplies reducing powerRead reaction 4L-Proline

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Reactions and enzymes

1 · Glutamate 5-kinase (ProB)

L-Glutamate → L-Glutamate-5-phosphate

Glutamate 5-kinase (ProB) · EC 2.7.2.11

Inputs, helpers or coproducts: ATP → ADP

2 · Glutamate-5-semialdehyde dehydrogenase (ProA)

L-Glutamate-5-phosphate → L-Glutamate-5-semialdehyde

Glutamate-5-semialdehyde dehydrogenase (ProA) · EC 1.2.1.41

Inputs, helpers or coproducts: NADPH supplies reducing power

3 · Spontaneous cyclization

L-Glutamate-5-semialdehyde → Δ¹-Pyrroline-5-carboxylate

Spontaneous cyclization

Inputs, helpers or coproducts: Water released

4 · Pyrroline-5-carboxylate reductase (ProC)

Δ¹-Pyrroline-5-carboxylate → L-Proline

Pyrroline-5-carboxylate reductase (ProC) · EC 1.5.1.2

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

Connected pathways

Glutamate and nitrogen assimilationArginine biosynthesis

Evidence and scope

Separate ProB and ProA activities are shown; fused enzymes also occur. 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 →