Evaluating atomic models of F-actin with an undecagold-tagged phalloidin derivative.
We have prepared an undecagold-tagged phalloidin derivative to determine this mushroom toxin's binding site and orientation within the F-actin filament by scanning transmission electron microscopy (STEM) and 3-D helical reconstruction. Remarkably, when stoichiometrically bound to F-actin, the undecagold moiety of the derivative could be directly visualized by STEM along the two half-staggered long-pitch helical strands of single filaments. Most importantly, the structural data obtained when combined with various biochemical constraints enabled us to critically evaluate two distinct atomic models of the F-actin filament (i.e. the Holmes-Lorenz versus the Schutt-Lindberg model). Taken together, our data are in excellent agreement with the Holmes-Lorenz model.
Steinmetz
M O
MO
M.E. Müller Institute for Microscopy, University of Basel, Switzerland.
Stoffler
D
D
Müller
S A
SA
Jahn
W
W
Wolpensinger
B
B
Goldie
K N
KN
Engel
A
A
Faulstich
H
H
Aebi
U
U
D000199:Actins / Q000737:chemistry / Q000378:metabolism / Q000648:ultrastructure*; D000818:Animals; D001665:Binding Sites; D017348:Microscopy, Electron, Scanning Transmission; D008958:Models, Molecular; D050607:Organogold Compounds; D009942:Organometallic Compounds / Q000737:chemistry*; D010590:Phalloidine / Q000737:chemistry / Q000378:metabolism*; D011485:Protein Binding; D011487:Protein Conformation; D011817:Rabbits
D000199:Actins; D050607:Organogold Compounds; D009942:Organometallic Compounds; D010590:Phalloidine; C035797:undecagold