김완태 (University of Texas at Austin (현 The Scripps Research Institute)) | 한빛사논문 > 한빛사

한빛사논문

조회228

University of Texas at Austin (현 The Scripps Research Institute)

CV File

ACS Catal., Jul 18 2025, 15 (14) | https://doi.org/10.1021/acscatal.5c03282 Studies of Isonitrile Synthases Help Elucidate the Mechanism of Isonitrile Installation

Tzu-Yu Chen ^{1 †}, Wantae Kim ^{2 † *}, Mo Guo ^{3 †}, Angela Yao ^{1 †}, Y Jessie Zhang ^{3 *}, Wei-Chen Chang ^{1 *}

¹Department of Chemistry, North Carolina State University, Raleigh, NC 27695, USA.
²McKetta Department of Chemical Engineering, University of Texas at Austin, Austin, TX 78712, USA.
³Department of Molecular Biosciences, University of Texas at Austin, Austin, TX 78712, USA.

^†T.-Y.C., W.K., M.G., and A.Y. contributed equally to this work.

^*Corresponding authors: correspondence to Wantae Kim, Y Jessie Zhang or Wei-Chen Chang

Abstract

Isonitrile functional group is abundant in natural products and associated with various biological properties. To date, two pathways are known for isonitrile group installation. One is catalyzed by mononuclear nonheme iron dependent isonitrilases in which the reaction mechanism involves consecutive desaturation and decarboxylation processes. The other pathway includes isonitrile synthases, however, how isonitrile synthases enable the condensation of a sugar phosphate and an aromatic amino acid to install isonitrile group remains understudied. In this study, we examine substrate analogs and quantify reaction products using isotopologues to establish the substrate requirements of two isonitrile synthases, WelI1 and PIsnA, providing insights into their spatial and substrate requirements. Under experimental conditions, isonitrile synthases can only enable single turnover, with product binding likely associated with this observation. To reveal the reaction mechanism, we solved substrate- and product-bound protein structures. Furthermore, using a sequential soaking approach, we successfully trapped a plausible intermediate in crystallo. Observation of the plausible C2-imine intermediate in the active site suggests the reaction starts from the imine installation between the carbonyl group of the sugar phosphate and the amine group of the amino acid. Altogether, these studies provide insights into substrate recognition, i.e., pentose phosphate and L-aromatic amino acid, and the reaction mechanism of isonitrile synthases.

논문정보