Fig. 1.

High-resolution maps of 96% acetylated (Ac⁹⁶) and <1% acetylated (Ac⁰) MTs. (A) Schematic of the model-building and refinement process in PHENIX. We sharpened a representative 4 × 3 lattice, refined the corresponding atomic structure (3JAR) into our map, and extracted out the central dimer to build additional residues into the αK40 loop. We performed this process iteratively for both the Ac⁹⁶ and Ac⁰. The structure of the Ac⁹⁶ (B) and Ac⁰ (C) αβ-tubulin heterodimers, respectively, are shown from the outer and luminal views with close-ups of αK40 loop in each state (D and E) low-pass filtered to 3.7 Å.