Fig. 4.

Acetylation may weaken lateral interactions. Close-up view of the lateral contacts between two α-tubulin monomers at a nonseam location (α1, light green; α2, dark green). K40 in α1 of the Ac⁰ state is 8 Å closer to the M-loop of α2 and appears to buttress the H1′–S2 loop, providing support for the vital α1K60–α2H283 lateral interaction. By contrast, that support is lost in the Ac⁹⁶ state because the acetylated K40 now packs much closer to the hydrophobic, inner core.