title: Structural model of channelrhodopsin.
abstract: Channelrhodopsins (ChRs) are light-gated cation channels that mediate ion transport across membranes in microalgae (vectorial catalysis). ChRs are now widely used for the analysis of neural networks in tissues and living animals with light (optogenetics). For elucidation of functional mechanisms at the atomic level, as well as for further engineering and application, a detailed structure is urgently needed. In the absence of an experimental structure, here we develop a structural ChR model based on several molecular computational approaches, capitalizing on characteristic patterns in amino acid sequences of ChR1, ChR2, Volvox ChRs, Mesostigma ChR, and the recently identified ChR of the halophilic alga Dunaliella salina. In the present model, we identify remarkable structural motifs that may explain fundamental electrophysiological properties of ChR2, ChR1, and their mutants, and in a crucial validation of the model, we successfully reproduce the excitation energy predicted by absorption spectra.
authors.affiliation: Institute of Physical Chemistry, Karlsruhe Institute of Technology, D-76131 Karlsruhe, Germany.
authors.forename: Hiroshi C
authors.initials: HC
authors.lastname: Watanabe
authors.forename: Kai
authors.initials: K
authors.lastname: Welke
authors.forename: Franziska
authors.initials: F
authors.lastname: Schneider
authors.forename: Satoshi
authors.initials: S
authors.lastname: Tsunoda
authors.forename: Feng
authors.initials: F
authors.lastname: Zhang
authors.forename: Karl
authors.initials: K
authors.lastname: Deisseroth
authors.forename: Peter
authors.initials: P
authors.lastname: Hegemann
authors.forename: Marcus
authors.initials: M
authors.lastname: Elstner
mesh_terms: D007473:Ion Channels / Q000737:chemistry*; D008958:Models, Molecular; D010940:Plant Proteins / Q000737:chemistry*; D020836:Protein Structure, Quaternary; D020539:Sequence Analysis, Protein; D044446:Volvox / Q000737:chemistry*
chemical_list: D007473:Ion Channels; D010940:Plant Proteins