7F0Y

Crystal structure of isomerase NsrQ F58A in complex with substrate analogue

Summary for 7F0Y

• Entry DOI: 10.2210/pdb7f0y/pdb
• Descriptor: NsrQ, methyl 2-[2,6-bis(oxidanyl)phenyl]carbonyl-5-methyl-3-oxidanyl-benzoate (3 entities in total)
• Functional Keywords: tetrahydroxanthones, blennolides, isomerase
• Biological source: Aspergillus novofumigatus
• Total number of polymer chains: 2
• Total formula weight: 38912.07

Authors

Yang, J.,Mori, T.,Abe, I. (deposition date: 2021-06-07, release date: 2022-04-20, Last modification date: 2023-11-29)

Primary citation

Yang, J.,Mori, T.,Wei, X.,Matsuda, Y.,Abe, I.
Structural Basis for Isomerization Reactions in Fungal Tetrahydroxanthone Biosynthesis and Diversification.
Angew.Chem.Int.Ed.Engl., 60:19458-19465, 2021

PubMed Abstract: The novel isomerase NsrQ, from Aspergillus novofumigatus, is a key enzyme in the biosynthesis of fungal tetrahydroxanthones and is responsible for dearomatizing cyclization to provide a tetrahydroxanthone scaffold. NsrQ catalyzes a two-step isomerization reaction, involving the isomerization of allylic alcohol and subsequent inversion of configuration at the methyl group. We report on the biochemical and structural characterizations of NsrQ, and its homologue Dcr3, from Diaporthe longicolla. The crystal structures of NsrQ and Dcr3 revealed their similar overall structures, with a cone-shaped α+β barrel fold, to those of the nuclear transport factor 2-like superfamily enzymes. Furthermore, the structures of Dcr3 and NsrQ variants complexed with substrate analogues and the site-directed mutagenesis studies identified the catalytic residues and the important hydrophobic residues in shaping the active site pocket for substrate binding. These enzymes thus utilize Glu and His residues as acid-base catalysts. Based on these observations, we proposed a detailed reaction mechanism for NsrQ-catalyzed isomerization reactions.

PubMed: 34180120
DOI: 10.1002/anie.202107884

Experimental method

X-RAY DIFFRACTION (1.6 Å)