Katanin Grips the β-Tubulin Tail through an Electropositive Double Spiral to Sever Microtubules.

ABSTRACT: The AAA ATPase katanin severs microtubules. It is critical in cell division, centriole biogenesis, and neuronal morphogenesis. Its mutation causes microcephaly. The microtubule templates katanin hexamerization and activates its ATPase. The structural basis for these activities and how they lead to severing is unknown. Here, we show that β-tubulin tails are necessary and sufficient for severing. Cryoelectron microscopy (cryo-EM) structures reveal the essential tubulin tail glutamates gripped by a double spiral of electropositive loops lining the katanin central pore. Each spiral couples allosterically to the ATPase and binds alternating, successive substrate residues, with consecutive residues coordinated by adjacent protomers. This tightly couples tail binding, hexamerization, and ATPase a

SUBMITTER: Zehr EA 

PROVIDER: S-EPMC7060837 | biostudies-literature | 2020 Jan

REPOSITORIES: biostudies-literature