3-Dimensional organization of the N-terminal vinculin head fragment.
The cytoskeleton-associated protein vinculin is composed of a globular head and an elongated tail domain. The protein can be cleaved by V8 protease treatment into two fragments with apparent molecular masses of 90 and 29/27 kDa, respectively. So far, no high-resolution data on the tertiary structure of the N-terminal 90-kDa fragment are available. We analyzed the 90-kDa fragment in detail, using electron spectroscopic imaging in conjunction with modelling experiments. The front view projection of this fragment appears roughly rhomboidal, with 4 intensity maxima arranged at the vertices and a stain-filled region in the center. Based on a detailed examination of different particle projections, a 3-dimensional model was constructed which appears as a flattened tetrahedron. A comparison of the 90-kDa fragment with the intact protein allows for a correlation between the subdomain organization of the vinculin head and the biochemically defined V8 protease cleavage sites (aa 851 and 857).
Winkler
J
J
Cell Biology, Zoological Institute, Technical University of Braunschweig, Germany. jorgw@yahoo.com
Jockusch
B M
BM
D000818:Animals; D001665:Binding Sites; D003599:Cytoskeleton / Q000378:metabolism; D004591:Electrophoresis, Polyacrylamide Gel; D005895:Gizzard, Avian / Q000737:chemistry; D008024:Ligands; D008854:Microscopy, Electron; D008958:Models, Molecular; D008962:Models, Theoretical; D011485:Protein Binding; D011487:Protein Conformation; D017434:Protein Structure, Tertiary; D012697:Serine Endopeptidases / Q000378:metabolism; D014422:Turkeys; D016596:Vinculin / Q000737:chemistry*
D008024:Ligands; D016596:Vinculin; D012697:Serine Endopeptidases; C028344:glutamyl endopeptidase