Structural insights into the substrate selectivity of alpha-oxoamine synthases from marine Vibrio sp. QWI-06.Chang, H.Y., Lo, L.H., Lan, Y.H., Hong, M.X., Chan, Y.T., Ko, T.P., Huang, Y.R., Cheng, T.H., Liaw, C.C.
(2022) Colloids Surf B Biointerfaces 210: 112224-112224
- PubMed: 34838420
- DOI: 10.1016/j.colsurfb.2021.112224
- Primary Citation of Related Structures:
- PubMed Abstract:
Pyridoxal phosphate (PLP)-dependent α-oxoamine synthases are generally believed to be responsible for offloading and elongating polyketides or catalyzing the condensation of amino acids and acyl-CoA thioester substrates, such as serine into sphingolipids and cysteate into sulfonolipids ...
Pyridoxal phosphate (PLP)-dependent α-oxoamine synthases are generally believed to be responsible for offloading and elongating polyketides or catalyzing the condensation of amino acids and acyl-CoA thioester substrates, such as serine into sphingolipids and cysteate into sulfonolipids. Previously, we discovered vitroprocines, which are tyrosine- and phenylalanine-polyketide derivatives, as potential new antibiotics from the genus Vibrio. Using bioinformatics analysis, we identified putative genes of PLP-dependent enzyme from marine Vibrio sp. QWI-06, implying a capability to produce amino-polyketide derivatives. One of these genes was cloned, and the recombinant protein, termed Vibrio sp. QWI-06 α-oxoamine synthases-1 (VsAOS1), was overexpressed for structural and biochemical characterization. The crystal structure of the dimeric VsAOS1 was determined at 1.8-Å resolution in the presence of L-glycine. The electron density map indicated a glycine molecule occupying the pyridoxal binding site in one monomer, suggesting a snapshot of the initiation process upon the loading of amino acid substrate. In mass spectrometry analysis, VsAOS1 strictly acted to condense L-glycine with C12 or C16 acyl-CoA, including unsaturated acyl analog. Furthermore, a single residue replacement of VsAOS1 (G243S) allowed the enzyme to generate sphingoid derivative when L-serine and lauroyl-CoA were used as substrates. Our data elucidate the mechanism of substrate binding and selectivity by the VsAOS1 and provide a thorough understanding of the molecular basis for the amino acid preference of AOS members.
Department of Marine Biotechnology and Resources, National Sun Yat-sen University, Kaohsiung, Taiwan; Graduate Institute of Natural Products, Kaohsiung Medical University, Kaohsiung, Taiwan; Graduate Institute of Pharmacognosy, Taipei Medical University, Taipei, Taiwan. Electronic address: email@example.com.