File:Pantothenic Acid Biosynthesis.svg
This route is followed by most bacteria like Escherichia coli, Salmonella typhimurium and Corynebacterium glutamicum. Importance of the routes may vary. E.g.: in S. typhimurium most of the α-ketoisovalerate is provided by dihydroxy-acid dehydratase.
Most plants and archaea follow a very similar route, and make B5 by joining pantoate and β-alanine.
α-ketoisovalerate can revert back to valine and vice versa.
All of the BCAT and valine-pyruvate transaminase substrates are not shown.
EC numbers are:
- 4.2.1.9 dihydroxy-acid dehydratase
- 2.6.1.42 BCAT (Branched-chain-amino-acid transaminase)
- 2.6.1.66 valine—pyruvate transaminase
- 2.1.2.11 ketopantoate hydroxymethyltransferase
- 1.1.1.169 ketopantoate reductase
- 1.1.1.86 ketol-acid reductoisomerase
- 4.1.1.11 aspartate 1-decarboxylase
- 6.3.2.1 pantothenate synthase
Sources:
- 1. Leonardi, R; Jackowski, S (2007). "Biosynthesis of Pantothenic Acid and Coenzyme A". EcoSal Plus. 2 (2). doi:10.1128/ecosalplus.3.6.3.4. ISSN 2324-6200.
- 2. Handbook of vitamins. Zempleni, J et al (4th ed.). Taylor & Francis. 2007. pp. 290–291. ISBN 9780849340222