(S)-usnate reductase

In enzymology, a (S)-usnate reductase (EC 1.1.1.199) is an enzyme that catalyzes the chemical reaction

(6R)-2-acetyl-6-(3-acetyl-2,4,6-trihydroxy-5-methylphenyl)-3-hydroxy-6- methyl-2,4-cyclohexadien-1-one + NAD⁺ ${\displaystyle \rightleftharpoons }$ (S)-usnic acid + NADH + H⁺

(S)-usnate reductase
Identifiers
EC no.	1.1.1.199
CAS no.	77237-99-1
Databases
IntEnz	IntEnz view
BRENDA	BRENDA entry
ExPASy	NiceZyme view
KEGG	KEGG entry
MetaCyc	metabolic pathway
PRIAM	profile
PDB structures	RCSB PDB PDBe PDBsum
Gene Ontology	AmiGO / QuickGO
Search PMC articles PubMed articles NCBI proteins

In the reverse direction, (S)-usnate is reduced by NADH with cleavage of the ether bond to form a 7-hydroxy group.

This enzyme belongs to the family of oxidoreductases, specifically those acting on the CH-OH group of donor with NAD⁺ or NADP⁺ as acceptor. The systematic name of this enzyme class is reduced-(S)-usnate:NAD⁺ oxidoreductase (ether-bond-forming). This enzyme is also called L-usnic acid dehydrogenase.