Structural Characteristics Of RxLR Effectors And Regulation Mechanism Of RxLR145

Oomycete plant pathogens secrete a large quantity of RxLR effectors when invading hosts.Our lab has already proven:(1)RxLR145 expressed at high levels during very early infection stages(1.5 h)of Phytophthora capsica.RxLR145,(2)PcRxLR145 inhibit cell death Nicotiana benthamiana caused by BAX,(3)PcRxLR145 can induce leafs necrosis of Nicotiana benthamiana.Here we get the crystal structures of PcRxLR145: The crystal's asymmetric unit contains two molecules;The N-terminal RxLR motif has no clear electron density and the C-terminus consists of five WY-domains linked with each other by one “linker” helix;Every WY-domain comprising 4 ?-helices,3 loops and two characteristic hydrophobic amino acids,frequently W(Trp)and Y(Tyr),which contribute to a stable hydrophobic core ?-helix.We compared all published RxLR effectors and found:(1)Almost all conformational differences exist in the K motif and Loop-3.This result proves that these two regions are under high evolutionary pressure.(2)Without linker helix the WY-domain cannot arrange in the same direction.We speculate that changing the arrange mode of WY domains is a evolutionary pattern of RxLR effectors.(3)ATR13 has a WY-like domain with N-terminus and C-terminus reversed.The head region of ATR1 is a WY-domain short of Y-motif.(4)The surface representation of RxLR effectors shows that the targets of this family maybe full of negative charge.RxLR145 can bind DNA sequence which belongs to MADS-box transcription factor and leucine zipper transcription factor to regulate gene expression of Ubiquitination,Ribosome,Metabolic pathways,and Oxidative phosphorylation.RxLR145 can influence 12849 genes in arabidopsis thaliana,with 6322 genes overexpressed and 6527 genes down expressed.These genes involve in Ubiquitination,Phosphorylation,Plant-pathogen interaction,Protein processing in endoplasmic reticulum,Regulation of autophagy,Endocytosis,and Plant hormone signal transduction.CHIP-Seq and RNA-Seq contain 662 kinds of pathway in common,including Ribosome,Translation,Regulation of amino acid metabolism,Ubiquitination,and Phosphorylation.Our results show that RxLR145 can combine DNA which encoding ubiquitination and phosphorylation proteins to suppression plant immunization.