MEP pathway products allosterically promote monomerization of deoxy-D-xylulose-5-phosphate synthase to feedback-regulate their supply  

作　　者：supply Xueni Di David Ortega-Alarcon Ramu Kakumanu Javier Iglesias-Fernandez Lucia Diaz Edward E.K.Baidoo Adrian Velazquez-Campoy Manuel Rodríguez-Concepción Jordi Perez-Gil 

机构地区：[1]Institute for Plant Molecular and Cell Biology(IBMCP),CSIC-Universitat Politècnica de València,46022 Valencia,Spain 2Centre for Research in Agricultural Genomics(CRAG),CSIC-IRTA-UAB-UB,Campus UAB Bellaterra,08193 Barcelona,Spain 3Institute for Biocomputation and Physics of Complex Systems(BIFI),Joint Unit GBsC-CSIC-BIFI,Universidad de Zaragoza,50009 Zaragoza,Spain 4Departamento de Bioquímica y Biología Molecular y Celular,Universidad de Zaragoza,50009 Zaragoza,Spain 5Joint BioEnergy Institute,5885 Hollis Street,Emeryville,CA 94608,USA 6Biological Systems and Engineering Division,Lawrence Berkeley National Laboratory,Berkeley,CA 94720,USA 7Nostrum Biodiscovery SL,08029 Barcelona,Spain 8Instituto de Investigación Sanitaria de Aragón(IIS Aragon),50009 Zaragoza,Spain 9Centro de Investigación Biomédica en Red en elÁrea Temática de Enfermedades Hepáticas y Digestivas(CIBERehd),28029 Madrid,Spain

出　　处：《Plant Communications》2023年第3期171-182,共12页植物通讯（英文）

基　　金：funded by grants from the Spanish MCIN/AEI/10.13039/501100011033;European ERDF/FEDER,NextGeneration EU/PRTR and PRIMA programs(PID2020-115810GB-I00;UToPIQ-PCI2021-121941 to M.R.-C.and BFU2016-78232-P to A.V.-C.).M.R.-C.is also supported by CSIC(202040E299);Generalitat Valenciana(PROMETEU/2021/056).R.K.and E.E.K.B.conducted the metabolite analysis at the Joint BioEnergy Institute(http://www.jbei.org),supported by the US Department of Energy,Office of Science,Office of Biological and Environmental Research under contract DE-AC02-05CH11231 between Lawrence Berkeley National Laboratory and the US Department of Energy.J.P.-G;was supported by a Marie Curie International Outgoing Fellowship within the EC-FP7 Program(project 627639);X.D.was supported by the China Scholarship Council and D.O.-A.by an MCIN/AEI/fellowship(BES-2017-080739).

摘　　要：Isoprenoids are a very large and diverse family of metabolites required by all living organisms.All isoprenoids derive fromthe double-bond isomers isopentenyl diphosphate(IPP)and dimethylallyl diphosphate(DMAPP),which are produced by the methylerythritol 4-phosphate(MEP)pathway in bacteria and plant plastids.It has been reported that IPP and DMAPP feedback-regulate the activity of deoxyxylulose 5-phosphate synthase(DXS),a dimeric enzyme that catalyzes the main flux-controlling step of the MEP pathway.Here we provide experimental insights intotheunderlyingmechanism.Isothermal titration calorimetry and dynamic light scattering approaches showed that IPP and DMAPP can allosterically bind to DXS in vitro,causing a size shift.In silico ligand binding site analysis and docking calculations identified a potential allosteric site in the contact region between the two monomers of the active DXS dimer.Modulation of IPP and DMAPP contents in vivo followed by immunoblot analyses confirmed that high IPP/DMAPP levels resulted in monomerization and eventual aggregation of the enzyme in bacterial and plant cells.Loss of the enzymatically active dimeric conformation allows a fast and reversible reduction of DXS activity in response to a sudden increase or decrease in IPP/DMAPP supply,whereas aggregation and subsequent removal of monomers that would otherwise be available for dimerization appears to be a more drastic response in the case of persistent IPP/DMAPP overabundance(e.g.,by a blockage in their conversion to downstream isoprenoids).Our results represent an important step toward understanding the regulation of the MEP pathway and rational design of biotechnological endeavors aimed at increasing isoprenoid contents in microbial and plant systems.

关 键 词：ISOPRENOIDS DXS feedback regulation ALLOSTERIC monomerization 

分 类 号：Q94[生物学—植物学]