Figure 6: Model mechanism for Alp14-driven plus end growth Alp14 (blue) binds Alp7 (orange) and the complex tracks plus ends using a combination of TOG-based binding and C-terminal non-TOG binding.
From: Alp7/TACC-Alp14/TOG generates long-lived, fast-growing MTs by an unconventional mechanism
Tubulin in the terminal layer of the GTP-cap can either exchange directly with GTP-tubulin in solution (via k1) or indirectly via the TOGs of Alp14 (via k2 and k3). Alp7 binding to the C-terminal tail domain of Alp14 potentiates Alp14 residency at plus ends. One possibility is that Alp7 blocks the transit of Alp14 into a putative autoinhibited state, shown at right.
