Common themes in redox chemistry emerge from the X-ray structure of oilseed rape (Brassica napus) enoyl acyl carrier protein reductase.
Rafferty, J.B., Simon, J.W., Baldock, C., Artymiuk, P.J., Baker, P.J., Stuitje, A.R., Slabas, A.R., Rice, D.W.(1995) Structure 3: 927-938
- PubMed: 8535786 
- DOI: https://doi.org/10.1016/S0969-2126(01)00227-1
- Primary Citation of Related Structures:  
1ENO, 1ENP - PubMed Abstract: 
Enoyl acyl carrier protein reductase (ENR) catalyzes the NAD(P)H-dependent reduction of trans-delta 2-enoyl acyl carrier protein, an essential step in de novo fatty acid biosynthesis. Plants contain both NADH-dependent and separate NADPH-dependent ENR enzymes which form part of the dissociable type II fatty acid synthetase. Highly elevated levels of the NADH-dependent enzyme are found during lipid deposition in maturing seeds of oilseed rape (Brassica napus). The crystal structure of an ENR-NAD binary complex has been determined at 1.9 A resolution and consists of a homotetramer in which each subunit forms a single domain comprising a seven-stranded parallel beta sheet flanked by seven alpha helices. The subunit has a topology highly reminiscent of a dinucleotide-binding fold. The active site has been located by difference Fourier analysis of data from crystals equilibrated in NADH. The structure of ENR shows a striking similarity with the epimerases and short-chain alcohol dehydrogenases, in particular, 3 alpha,20 beta-hydroxysteroid dehydrogenase (HSD). The similarity with HSD extends to the conservation of a catalytically important lysine that stabilizes the transition state and to the use of a tyrosine as a base--with subtle modifications arising from differing requirements of the reduction chemistry.
Organizational Affiliation: 
Krebs Institute for Biomolecular Research, Department of Molecular Biology and Biotechnology, University of Sheffield, UK.