@article{ac2f09357bbf406b85f8ea3d2e716647,
title = "Investigating the reaction and substrate preference of indole-3-acetaldehyde dehydrogenase from the plant pathogen pseudomonas syringae PtoDC3000",
abstract = "Aldehyde dehydrogenases (ALDHs) catalyze the conversion of various aliphatic and aromatic aldehydes into corresponding carboxylic acids. Traditionally considered as housekeeping enzymes, new biochemical roles are being identified for members of ALDH family. Recent work showed that AldA from the plant pathogen Pseudomonas syringae strain PtoDC3000 (PtoDC3000) functions as an indole-3-acetaldehyde dehydrogenase for the synthesis of indole-3-acetic acid (IAA). IAA produced by AldA allows the pathogen to suppress salicylic acid-mediated defenses in the model plant Arabidopsis thaliana. Here we present a biochemical and structural analysis of the AldA indole-3-acetaldehyde dehydrogenase from PtoDC3000. Site-directed mutants targeting the catalytic residues Cys302 and Glu267 resulted in a loss of enzymatic activity. The X-ray crystal structure of the catalytically inactive AldA C302A mutant in complex with IAA and NAD+ showed the cofactor adopting a conformation that differs from the previously reported structure of AldA. These structures suggest that NAD+ undergoes a conformational change during the AldA reaction mechanism similar to that reported for human ALDH. Site-directed mutagenesis of the IAA binding site indicates that changes in the active site surface reduces AldA activity; however, substitution of Phe169 with a tryptophan altered the substrate selectivity of the mutant to prefer octanal. The present study highlights the inherent biochemical versatility of members of the ALDH enzyme superfamily in P. syringae.",
author = "Kaleena Zhang and Lee, {Josephine S.} and Regina Liu and Chan, {Zita T.} and Dawson, {Trenton J.} and {de Togni}, {Elisa S.} and Edwards, {Chris T.} and Eng, {Isabel K.} and Gao, {Ashley R.} and Goicouria, {Luis A.} and Hall, {Erin M.} and Hu, {Kelly A.} and Katherine Huang and Alexander Kizhner and Kodama, {Kelsie C.} and Lin, {Andrew Z.} and Liu, {Jennifer Y.} and Lu, {Alan Y.} and Peng, {Owen W.} and Ryu, {Erica P.} and Sophia Shi and Sorkin, {Maria L.} and Walker, {Patricia L.} and Wang, {Grace J.} and Xu, {Mark C.} and Yang, {Rebecca S.} and Barrie Cascella and Wilhelm Cruz and Holland, {Cynthia K.} and McClerkin, {Sheri A.} and Kunkel, {Barbara N.} and Lee, {Soon Goo} and Jez, {Joseph M.}",
note = "Funding Information: This work was supported by the National Science Foundation [grant numbers IOS-164590 8 (to B.N.K.), and MCB-1614539 (to J.M.J.)]; the Howard Hughes Medical Institute Science Education Program (to J.M.J.); and the NSF Graduate Research Fellowships [grant number DGE-1143954 (to C.K.H. and M.L.S.)]. This project was part of Bio4522, an upper-level lab course at Washington University in St. Louis. Portions of this research were carried out at the Argonne National Laboratory Structural Biology Center of the Advanced Photon Source, a national user facility operated by the University of Chicago for the Department of Energy Office of Biological and Environmental Research (DE-AC02-06CH11357). Publisher Copyright: {\textcopyright} 2020 The Author(s). This is an open access article published by Portland Press Limited on behalf of the Biochemical Society and distributed under the Creative Commons Attribution License 4.0 (CC BY).",
year = "2020",
month = dec,
doi = "10.1042/BSR20202959",
language = "English",
volume = "40",
journal = "Bioscience Reports",
issn = "0144-8463",
number = "12",
}