The 3D structure of villin as an unusual F-Actin crosslinker.
Villin is an F-actin nucleating, crosslinking, severing, and capping protein within the gelsolin superfamily. We have used electron tomography of 2D arrays of villin-crosslinked F-actin to generate 3D images revealing villin's crosslinking structure. In these polar arrays, neighboring filaments are spaced 125.9 +/- 7.1 A apart, offset axially by 17 A, with one villin crosslink per actin crossover. More than 6500 subvolumes containing a single villin crosslink and the neighboring actin filaments were aligned and classified to produce 3D subvolume averages. Placement of a complete villin homology model into the average density reveals that full-length villin binds to different sites on F-actin from those used by other actin-binding proteins and villin's close homolog gelsolin.
Hampton
Cheri M
CM
Institute of Molecular Biophysics, Florida State University, Tallahassee, FL 32306-4380, USA.
Liu
Jun
J
Taylor
Dianne W
DW
DeRosier
David J
DJ
Taylor
Kenneth A
KA
D008841:Actin Cytoskeleton / Q000235:genetics / Q000378:metabolism; D000199:Actins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D000595:Amino Acid Sequence; D000818:Animals; D001665:Binding Sites; D002645:Chickens; D003432:Cross-Linking Reagents / Q000737:chemistry* / Q000378:metabolism*; D007091:Image Processing, Computer-Assisted; D021621:Imaging, Three-Dimensional; D007422:Intestines / Q000737:chemistry; D008840:Microfilament Proteins / Q000737:chemistry* / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism* / Q000648:ultrastructure; D008958:Models, Molecular; D008969:Molecular Sequence Data; D008970:Molecular Weight; D018482:Muscle, Skeletal / Q000737:chemistry; D011485:Protein Binding; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary / Q000235:genetics; D011817:Rabbits; D017386:Sequence Homology, Amino Acid
D000199:Actins; D003432:Cross-Linking Reagents; D008840:Microfilament Proteins; C026615:villin