Three-dimensional reconstructions provide accurate geometric and spatial representations of macromolecular complexes found at synpases.

Determining the 3-D structure of CaM kinase II (CaMKII) is one of our key endeavors. We accomplish this through 3-D reconstruction of single particle images collected by stain and cyro-electron microscopy. These efforts are in collaboration with Dr. James Stoops and Dr. Pawel Penczek.

CaMKII resists crystallization and is too large for analysis by NMR. Therefore, cryo-electron microscopy followed by 3-D reconstructions is the only means of producing data on the 3-D structure of CaMKII holoenzymes. We have successfully accomplished this goal, and a low resolution structure (23A) is shown in Figure 1. This recombinant form of the neuronal (alpha) isoform of CaMKII is a twelve-subunit complex. The catalytic domains reside in foot-like processes that extend away from a central gear-shaped core formed by the C-terminal domains of each subunit.

                                                                                                                                                                                                           Figure 1.  Click to enlarge

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