Initial three-dimensional reconstructions of protein kinase C delta from two-dimensional crystals on lipid monolayers.
Two-dimensional crystals of protein kinase C delta (PKCdelta) and of its regulatory domain (RDdelta) were grown on lipid monolayers and analyzed by electron microscopy at tilt angles varying from -50 degrees to +55 degrees. Although the crystals exhibit pseudo-3-fold symmetry, analysis of difference phase residuals indicates that there is only one way to align the crystals for merging so the data were processed in plane group P1. Three-dimensional reconstructions generated for several two-dimensional crystals each of PKCdelta and RDdelta show good agreement and are consistent with membrane attachment via a single C1 subdomain, a small surface contact by one or two loops from the C2 domain, and, in intact PKCdelta, a small appendage from the catalytic domain, probably V5. Two-dimensional crystallography with three-dimensional reconstruction should be suitable for examination of additional PKC isozymes and for analysis of the enzymes bound to substrates and other proteins.
Solodukhin
Alexander S
AS
Department of Anesthesiology, University of Virginia, Charlottesville, VA 22908, USA. as4j@virginia.edu
Kretsinger
Robert H
RH
Sando
Julianne J
JJ
D003460:Crystallization; D021621:Imaging, Three-Dimensional; D008563:Membrane Lipids / Q000737:chemistry; D008958:Models, Molecular; D051745:Protein Kinase C-delta / Q000737:chemistry / Q000648:ultrastructure*; D017434:Protein Structure, Tertiary
D008563:Membrane Lipids; D051745:Protein Kinase C-delta