structural and functional analysis of phytotoxin toxoflavin-degrading enzyme结构和功能分析的植物毒素toxoflavin-degrading酶.pdf

Structural and Functional Analysis of Phytotoxin Toxoflavin-Degrading Enzyme 1. 1. 1 2 2 1 Woo-Suk Jung , Jeehyun Lee , Myung-Il Kim , Jun Ma , Tomohisa Nagamatsu , Eunhye Goo , 1 1 3 1,4 Hongsup Kim , Ingyu Hwang , Jaehong Han , Sangkee Rhee * 1 Department of Agricultural Biotechnology, Seoul National University, Seoul, Korea, 2 Division of Pharmaceutical Sciences, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama, Japan, 3 Department of Biotechnology, Chung-Ang University, Anseong, Korea, 4 Center for Fungal Pathogenesis, Seoul National University, Seoul, Korea Abstract Pathogenic bacteria synthesize and secrete toxic low molecular weight compounds as virulence factors. These microbial toxins play essential roles in the pathogenicity of bacteria in various hosts, and are emerging as targets for antivirulence strategies. Toxoflavin, a phytotoxin produced by Burkholderia glumae BGR1, has been known to be the key factor in rice grain rot and wilt in many field crops. Recently, toxoflavin-degrading enzyme (TxDE) was identified from Paenibacillus polymyxa JH2, thereby providing a possible antivirulence strategy for toxoflavin-mediated plant diseases. Here, we report the crystal structure of TxDE in the substrate-free form and in complex with toxoflavin, along with the results of a functional analysis. The overall structure of TxDE is similar to those of the vicinal oxygen chelate superfamily of metalloenzymes,