Glutamate-5-semialdehyde is a non-proteinogenic amino acid involved in both the biosynthesis and degradation of proline and arginine (via ornithine),[1][2] as well as in the biosynthesis of antibiotics, such as carbapenems.

It is synthesized by the reduction of glutamyl-5-phosphate by glutamate-5-semialdehyde dehydrogenase.

Reduction of glutamic acid semialdehyde with sodium borohydride gives hydroxyaminovaleric acid.

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