College of Life Sciences, National Laboratory of Plant Genetic Engineering and Protein Engineering, Center for Bioinformatics, Peking University, Beijing 100871, PR China. liz@mail.cbi.pku.edu.cn|College of Life Sciences, National Laboratory of Plant Genetic Engineering and Protein Engineering, Center for Bioinformatics, Peking University, Beijing 100871, PR China. liz@mail.cbi.pku.edu.cn|College of Life Sciences, National Laboratory of Plant Genetic Engineering and Protein Engineering, Center for Bioinformatics, Peking University, Beijing 100871, PR China. liz@mail.cbi.pku.edu.cn|College of Life Sciences, National Laboratory of Plant Genetic Engineering and Protein Engineering, Center for Bioinformatics, Peking University, Beijing 100871, PR China. liz@mail.cbi.pku.edu.cn|College of Life Sciences, National Laboratory of Plant Genetic Engineering and Protein Engineering, Center for Bioinformatics, Peking University, Beijing 100871, PR China. liz@mail.cbi.pku.edu.cn|College of Life Sciences, National Laboratory of Plant Genetic Engineering and Protein Engineering, Center for Bioinformatics, Peking University, Beijing 100871, PR China. liz@mail.cbi.pku.edu.cn