3QWI

Crystal structure of a 17beta-hydroxysteroid dehydrogenase (holo form) from fungus Cochliobolus lunatus in complex with NADPH and coumestrol

Summary for 3QWI

• Entry DOI: 10.2210/pdb3qwi/pdb
• Related: 3IS3 3ITD 3QWF 3QWH
• Descriptor: 17beta-hydroxysteroid dehydrogenase, NADP NICOTINAMIDE-ADENINE-DINUCLEOTIDE PHOSPHATE, Coumestrol, ... (5 entities in total)
• Functional Keywords: 17beta-hydroxysteroid dehydrogenase, short chain dehydrogenase/reductase, phytoestrogens, flavonoid, rossmann fold, cytosol, oxidoreductase-oxidoreductase inhibitor complex, oxidoreductase/oxidoreductase inhibitor
• Biological source: Cochliobolus lunatus
• Total number of polymer chains: 4
• Total formula weight: 120083.07

Authors

Cassetta, A.,Lamba, D.,Krastanova, I.,Stojan, J.,Lanisnik Rizner, T.,Kristan, K.,Brunskole, M. (deposition date: 2011-02-28, release date: 2012-01-18, Last modification date: 2023-09-13)

Primary citation

Cassetta, A.,Krastanova, I.,Kristan, K.,Brunskole Svegelj, M.,Lamba, D.,Lanisnik Rizner, T.,Stojan, J.
Structural studies on the flavonoid inhibition of a fungal 17Beta-Hydroxysteroid dehydrogenase
Biochem.J., 441:151-160, 2012

PubMed Abstract: The 17β-HSD (17β-hydroxysteroid dehydrogenase) from the filamentous fungus Cochliobolus lunatus (17β-HSDcl) is a NADP(H)-dependent enzyme that preferentially catalyses the interconversion of inactive 17-oxo-steroids and their active 17β-hydroxy counterparts. 17β-HSDcl belongs to the SDR (short-chain dehydrogenase/reductase) superfamily. It is currently the only fungal 17β-HSD member that has been described and represents one of the model enzymes of the cP1 classical subfamily of NADPH-dependent SDR enzymes. A thorough crystallographic analysis has been performed to better understand the structural aspects of this subfamily and provide insights into the evolution of the HSD enzymes. The crystal structures of the 17β-HSDcl apo, holo and coumestrol-inhibited ternary complex, and the active-site Y167F mutant reveal subtle conformational differences in the substrate-binding loop that probably modulate the catalytic activity of 17β-HSDcl. Coumestrol, a plant-derived non-steroidal compound with oestrogenic activity, inhibits 17β-HSDcl [IC50 2.8 μM; at 100 μM substrate (4-oestrene-3,17-dione)] by occupying the putative steroid-binding site. In addition to an extensive hydrogen-bonding network, coumestrol binding is stabilized further by π-π stacking interactions with Tyr212. A stopped-flow kinetic experiment clearly showed the coenzyme dissociation as the slowest step of the reaction and, in addition to the low steroid solubility, it prevents the accumulation of enzyme-coenzyme-steroid ternary complexes.

PubMed: 21929506
DOI: 10.1042/BJ20110567

Experimental method

X-RAY DIFFRACTION (2.5 Å)