1 Departments of Chemistry and Biochemistry and Biological Chemistry, UCLA-DOE Institute and Howard Hughes Medical Institute, UCLA, Los Angeles, CA, USA.
2 Department of Neurology, Molecular Biology Institute and Brain Research Institute, UCLA, Los Angeles, CA, USA.
3 Department of Chemistry and Biochemistry, UCLA, Los Angeles, CA, USA.
4 Department of Microbiology, Immunology and Molecular Genetics, David Geffen School of Medicine, UCLA, Los Angeles, CA, USA.
5 Systems Neurobiology Laboratory, The Salk Institute for Biological Studies, La Jolla, CA, USA.
6 Division of Applied Mathematics, Brown University, Providence, RI, USA.
7 Departments of Chemistry and Biochemistry and Biological Chemistry, UCLA-DOE Institute and Howard Hughes Medical Institute, UCLA, Los Angeles, CA, USA. david@mbi.ucla.edu.
8 Department of Neurology, Molecular Biology Institute and Brain Research Institute, UCLA, Los Angeles, CA, USA. jianglin@ucla.edu.
In the version of this Article originally published online, the upper right panel of Fig. 5a was mistakenly a repeat of the lower right panel. This has now been corrected in all versions of the Article.