A novel RPMXR motif among class II 5-enolpyruvylshikimate-3-phosphate synthases is required for enzymatic activity and glyphosate resistance.
The shikimate pathway enzyme 5-enolpyruvylshikimate-3-phosphate (EPSP) synthase is an attractive target for drugs and herbicides. Here we identified a novel RPMXR motif that is strictly conserved among class II EPSP synthases. Site-directed mutational analysis of this motif showed that substitutions of the four strictly conserved amino acid residues, Arg127, Pro128, Met129, and Arg131, resulted in complete loss of enzymatic activity, whereas changes in the non-conserved Asn130 residue strongly influenced glyphosate resistance (all numbering according to Pseudomonas stutzeri A1501 EPSP synthase). These experimental results, combined with 3D structure modeling of the location and interaction of the RPMXR motif with phosphoenolpyruvate (PEP) and shikimate-3-phosphate (S3P), demonstrate that the novel motif is required for enzymatic activity and glyphosate resistance of class II EPSP synthases.
Biotechnology Research Institute, Chinese Academy of Agricultural Sciences/Key Laboratory of Crop Biotechnology, Ministry of Agriculture, Beijing 100081, China.
Liang
L
Li
Wei
W
Lu
Yunlei
Y
Han
Shuzhen
S
Ping
Wei
W
Zhang
Ming
M
Chen
Zhonglin
Z
Zhao
Yongliang
Y
Yan
Yan
Y
Jiang
Min
M
Lin
D051229:3-Phosphoshikimate 1-Carboxyvinyltransferase / Q000037:antagonists & inhibitors / Q000737:chemistry* / Q000378:metabolism*; D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D017124:Conserved Sequence; D024881:Drug Resistance, Bacterial; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D004926:Escherichia coli / Q000187:drug effects* / Q000201:enzymology* / Q000235:genetics; D005998:Glycine / Q000031:analogs & derivatives* / Q000494:pharmacology; D008958:Models, Molecular; D016297:Mutagenesis, Site-Directed; D010728:Phosphoenolpyruvate / Q000378:metabolism; D012765:Shikimic Acid / Q000031:analogs & derivatives / Q000378:metabolism; D013329:Structure-Activity Relationship; D000097797:Glyphosate
D051229:3-Phosphoshikimate 1-Carboxyvinyltransferase; D004791:Enzyme Inhibitors; D005998:Glycine; D010728:Phosphoenolpyruvate; D012765:Shikimic Acid; D000097797:Glyphosate; C042786:shikimic acid-3-phosphate