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From Proteopedia
crystal structure of human katanin AAA ATPase domain
Structural highlights
FunctionKTNA1_HUMAN Catalytic subunit of a complex which severs microtubules in an ATP-dependent manner. Microtubule severing may promote rapid reorganization of cellular microtubule arrays and the release of microtubules from the centrosome following nucleation. Microtubule release from the mitotic spindle poles may allow depolymerization of the microtubule end proximal to the spindle pole, leading to poleward microtubule flux and poleward motion of chromosome. Microtubule release within the cell body of neurons may be required for their transport into neuronal processes by microtubule-dependent motor proteins. This transport is required for axonal growth.[HAMAP-Rule:MF_03023][1] [2] [3] Publication Abstract from PubMedKatanin was the first microtubule (MT)-severing enzyme discovered, but how katanin executes MT severing remains poorly understood. Here, we report X-ray crystal structures of the apo and ATPgammaS-bound states of the catalytic AAA domain of human katanin p60 at 3.0 and 2.9 A resolution, respectively. Comparison of the two structures reveals conformational changes induced by ATP binding and how such changes ensure hexamer stability. Moreover, we uncover structural details of pore loops (PLs) and show that Arg283, a residue unique to katanin among MT-severing enzymes, protrudes from PL1 and lines the entry of the catalytic pore. Functional studies suggest that PL1 and Arg283 play essential roles in the recognition and remodeling of the glutamylated, C-terminal tubulin tail and regulation of axon growth. In addition, domain-swapping experiments in katanin and spastin suggest that the non-homologous N-terminal region, which contains the MT-interacting and trafficking domain and a linker, confers specificity to the severing process. Structural and Molecular Basis for Katanin-Mediated Severing of Glutamylated Microtubules.,Shin SC, Im SK, Jang EH, Jin KS, Hur EM, Kim EE Cell Rep. 2019 Jan 29;26(5):1357-1367.e5. doi: 10.1016/j.celrep.2019.01.020. PMID:30699360[4] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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