Cofactors

There are no Cofactors for this Enzyme

Reaction Mechanism

enoyl-[acyl-carrier-protein] reductase (NADPH, B-specific) By Reference

2-enoyl thioester reductases catalyse the reduction of trans-2-enoyl acyl carrier protein/coenzyme A to acyl carrier protein/coenzyme A. Yeast enzymes, such as Etr1p and Mrf1p, are responsible for the NADPH dependent reaction in mitochondrial fatty acid synthesis, and are indispensible for respiratory function in yeast. They belong to the medium chain dehydrogenases/reductases (MDR) superfamily and are structurally distinguishable from the prokaryotic 2-enoyl thioester which belong to the short chain dehydrogenases/reductases (SDR) superfamily. The Candida tropicalis genes ETR1 and ETR2 both encode enzymatically active 2-enoyl thioester reductases, which can form both homodimers and heterodimers.




• Summary
• Step 1
• Step 2
• Products

The proposed mechanism is based on analogy with the prokaryotic enoyl thioester reductases such as InhA. A hydride is transferred from NADPH to the beta position of the alpha-beta unsaturated carbonyl substrate (Michael addition) to give an enol(ate) intermediate. The hydroxy group of Tyr 79 acts as an electrophilic catalyst by forming a hydrogen bond to the substrate carbonyl to stabilise the intermediate and the transition state leading to it.

Catalytic Residues

AA	Uniprot	Uniprot Resid	PDB	PDB Resid
Tyr	Q8WZM3	79	1guf	57

Step Components

overall reactant used, overall product formed, proton transfer, intermediate formation, aromatic unimolecular elimination by the conjugate base, cofactor used, intermediate collapse, hydride transfer, michael addition



Step 1.

Tyr79 acts as an electrophilic catalyst by hydrogen bonding to the carbonyl group of alpha-beta unsaturated carbonyl substrate. A hydride is transferred from NADPH to the beta-position in a conjugate addition reaction, forming an intermediate enolate and NADP.



Step 2.

The enolate intermediate collapses and the substrate is protonated at the alpha-carbon, forming the reduced product.



Products.

The products of the reaction.

View Reaction Mechanisms in M-CSA

Reaction Parameters

There are no kinetic parameters information for this Enzyme

Associated Proteins

Citations

• Microbe-Responsive Proteomes During Plant-Microbe Interactions Between Rice Genotypes and the Multifunctional Methylobacterium oryzae CBMB20.
• Enhancement of functional activity and biosynthesis of exopolysaccharides in Monascus purpureus by genistein treatments.
• Characterization of protein-ligand binding interactions of enoyl-ACP reductase (FabI) by native MS reveals allosteric effects of coenzymes and the inhibitor triclosan.
• Methanol-based biomanufacturing of fuels and chemicals using native and synthetic methylotrophs.
• RNA-seq analysis reveals genes related to photosynthetic carbon partitioning and lipid production in Phaeodactylum tricornutum under alkaline conditions.
• Ageing and rejuvenation models reveal changes in key microbial communities associated with healthy ageing.
• Path to Actinorhodin: Regio- and Stereoselective Ketone Reduction by a Type II Polyketide Ketoreductase Revealed in Atomistic Detail.
• Biosynthesis of 6-Hydroxymellein Requires a Collaborating Polyketide Synthase-like Enzyme.
• Discovery of New Carbonyl Reductases Using Functional Metagenomics and Applications in Biocatalysis.
• Tungsten enzymes play a role in detoxifying food and antimicrobial aldehydes in the human gut microbiome.
• CREB-Regulated Transcriptional Coactivator 2 Proteome Landscape is Modulated by SREBF1.