8EQW

Crystal structure of Fub7

Summary for 8EQW

• Entry DOI: 10.2210/pdb8eqw/pdb
• Descriptor: Sulfhydrylase FUB7 (2 entities in total)
• Functional Keywords: c-c bond formation, biosynthetic protein
• Biological source: Fusarium fujikuroi
• Total number of polymer chains: 8
• Total formula weight: 395720.84

Authors

Hai, Y. (deposition date: 2022-10-10, release date: 2023-10-11, Last modification date: 2024-03-27)

Primary citation

Liu, S.,Yeh, C.,Reavill, C.,Jones, B.,Zou, Y.,Hai, Y.
Molecular and Structural Basis for C gamma-C Bond Formation by PLP-Dependent Enzyme Fub7.
Angew.Chem.Int.Ed.Engl., 63:e202317161-e202317161, 2024

PubMed Abstract: Pyridoxal 5'-phosphate (PLP)-dependent enzymes that catalyze γ-replacement reactions are prevalent, yet their utilization of carbon nucleophile substrates is rare. The recent discovery of two PLP-dependent enzymes, CndF and Fub7, has unveiled unique C-C bond forming capabilities, enabling the biocatalytic synthesis of alkyl- substituted pipecolic acids from O-acetyl-L-homoserine and β-keto acid or aldehyde derived enolates. This breakthrough presents fresh avenues for the biosynthesis of pipecolic acid derivatives. However, the catalytic mechanisms of these enzymes remain elusive, and a dearth of structural information hampers their extensive application. Here, we have broadened the catalytic scope of Fub7 by employing ketone-derived enolates as carbon nucleophiles, revealing Fub7's capacity for substrate-dependent regioselective α-alkylation of unsymmetrical ketones. Through an integrated approach combining X-ray crystallography, spectroscopy, mutagenesis, and computational docking studies, we offer a detailed mechanistic insight into Fub7 catalysis. Our findings elucidate the structural basis for its substrate specificity, stereoselectivity, and regioselectivity. Our work sets the stage ready for subsequent protein engineering effort aimed at expanding the synthetic utility of Fub7, potentially unlocking novel methods to access a broader array of noncanonical amino acids.

PubMed: 38308582
DOI: 10.1002/anie.202317161

Experimental method

X-RAY DIFFRACTION (1.76 Å)