Fig. 5.

Seam opening correlates with GTP hydrolysis and MT instability. The panels correspond to MT cross-sections for both GTP-like and GDP-MTs showing comparison between the symmetrized and C1 maps to illustrate the break of symmetry with the opening between pfs at the seam for some of the MTs studied. (A) Wt MTs in a posthydrolysis state show the seam-opening phenomenon localized to the pfs at the seam. Movie S4 allows for a dynamic visualization of this motion. (B) GTPγS copolymerized with EB3 originally from data collected for the map deposited as EMD-6347 (8). (C) Undecorated E254N MTs. (D) Undecorated E254A MTs. (E) The E254A MT copolymerized with EB3. No seam opening is seen for B, C, D, or E.