5IQY

Structure of apo-Dehydroascorbate Reductase from Pennisetum Glaucum phased by Iodide-SAD method

Summary for 5IQY

• Entry DOI: 10.2210/pdb5iqy/pdb
• Descriptor: Dehydroascorbate reductase, IODIDE ION (3 entities in total)
• Functional Keywords: dehydroascorbate reductase, iodide-sad method, oxidoreductase
• Biological source: Pennisetum americanum (Pearl millet,Cenchrus americanus)
• Total number of polymer chains: 1
• Total formula weight: 27025.71

Authors

Das, B.K.,Kumar, A.,Manidola, P.,Arockiasamy, A. (deposition date: 2016-03-11, release date: 2016-05-04, Last modification date: 2024-03-20)

Primary citation

Das, B.K.,Kumar, A.,Maindola, P.,Mahanty, S.,Jain, S.K.,Reddy, M.K.,Arockiasamy, A.
Non-native ligands define the active site of Pennisetum glaucum (L.) R. Br dehydroascorbate reductase
Biochem.Biophys.Res.Commun., 473:1152-1157, 2016

PubMed Abstract: Dehydroascorbate reductase (DHAR), a member of the glutathione-S-transferase (GST) family, reduces dehydroascorbate (DHA) to ascorbate (AsA; Vitamin-C) in a glutathione (GSH)-dependent manner and in doing so, replenishes the critical AsA pool of the cell. To understand the enzyme mechanism in detail, we determined the crystal structure of a plant DHAR from Pennisetum glaucum (PgDHAR) using Iodide-Single Anomalous Dispersion (SAD) and Molecular replacement methods, in two different space groups. Here, we show PgDHAR in complex with two non-native ligands, viz. an acetate bound at the G-site, which resembles the γ-carboxyl moiety of GSH, and a glycerol at the H-site, which shares the backbone of AsA. We also show that, in the absence of bound native substrates, these non-native ligands help define the critical 'hook points' in the DHAR enzyme active site. Further, our data suggest that these non-native ligands can act as the logical bootstrapping points for iterative design of inhibitors/analogs for DHARs.

PubMed: 27067046
DOI: 10.1016/j.bbrc.2016.04.031

Experimental method

X-RAY DIFFRACTION (2.4 Å)