Hydrolysis-deficient mosaic microtubules as faithful mimics of the GTP cap.

ABSTRACT: A critical feature of microtubules is their GTP cap, a stabilizing GTP-tubulin rich region at growing microtubule ends. Microtubules polymerized in the presence of GTP analogs or from GTP hydrolysis-deficient tubulin mutants have been used as GTP-cap mimics for structural and biochemical studies. However, these analogs and mutants generate microtubules with diverse biochemical properties and lattice structures, leaving it unclear what is the most faithful GTP mimic and hence the structure of the GTP cap. Here, we generate a hydrolysis-deficient human tubulin mutant, αE254Q, with the smallest possible modification. We show that αE254Q-microtubules are stable, but still exhibit mild mutation-induced growth abnormalities. However, mixing two GTP hydrolysis-deficient tubulin mutants, αE254Q an

SUBMITTER: Estevez-Gallego J 

PROVIDER: S-EPMC11893814 | biostudies-literature | 2025 Mar

REPOSITORIES: biostudies-literature