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Combining electron crystallography and X-ray crystallography to study the MlotiK1 cyclic nucleotide-regulated potassium channel.

ABSTRACT: We have recently reported the X-ray structure of the cyclic nucleotide-regulated potassium channel, MlotiK1. Here we describe the application of both electron and X-ray crystallography to obtain high quality crystals. We suggest that the combined application of these techniques provides a useful strategy for membrane protein structure determination. We also present negative stain projection and cryo-data projection maps. These maps provide new insights about the properties of the MlotiK1 channel. In particular, a comparison of a 9A cryo-data projection with calculated model maps strongly suggests that there is a very weak interaction between the pore and the S1-S4 domains of this 6 TM tetrameric cation channel and that the S1-S4 domains can adopt multiple orientations relative to the pore.

SUBMITTER: Clayton GM

PROVIDER: S-EPMC2922748 | biostudies-literature | 2009 Sep

REPOSITORIES: biostudies-literature

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Combining electron crystallography and X-ray crystallography to study the MlotiK1 cyclic nucleotide-regulated potassium channel.

Clayton Gina M GM Aller Steve G SG Wang Jimin J Unger Vinzenz V Morais-Cabral João H JH

Journal of structural biology 20090621 3

We have recently reported the X-ray structure of the cyclic nucleotide-regulated potassium channel, MlotiK1. Here we describe the application of both electron and X-ray crystallography to obtain high quality crystals. We suggest that the combined application of these techniques provides a useful strategy for membrane protein structure determination. We also present negative stain projection and cryo-data projection maps. These maps provide new insights about the properties of the MlotiK1 channel ...[more]

PMID: 19545635

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