Miyake Y Keusch JJ Wang L Saito M Hess D Wang X Melancon BJ Helquist P Gut H Matthias P 2016 We report crystal structures of zebrafish histone deacetylase 6 (HDAC6) catalytic domains in tandem or as single domains in complex with the (R) and (S) enantiomers of trichostatin A (TSA) or with the HDAC6-specific inhibitor nexturastat A. The tandem domains formed, together with the inter-domain linker, an ellipsoid-shaped complex with pseudo-twofold symmetry. We identified important active site differences between both catalytic domains and revealed the binding mode of HDAC6 selective inhibitors. HDAC inhibition assays with (R)- and (S)-TSA showed that (R)-TSA was a broad-range inhibitor, whereas (S)-TSA had moderate selectivity for HDAC6. We identified a uniquely positioned α-helix and a flexible tryptophan residue in the loop joining α-helices H20 to H21 as critical for deacetylation of the physiologic substrate tubulin. Using single-molecule measurements and biochemical assays we demonstrated that HDAC6 catalytic domain 2 deacetylated α-tubulin lysine 40 in the lumen of microtubules, but that its preferred substrate was unpolymerized tubulin. https://sonar.ch/global/documents/17621 eng info:eu-repo/semantics/altIdentifier/doi/10.1038/nchembio.2140 info:eu-repo/semantics/altIdentifier/pmid/27454931 Nature chemical biology. - 2016 Acetylation Animals Biocatalysis Histone Deacetylase 6 Histone Deacetylase Inhibitors Histone Deacetylases Humans Hydroxamic Acids Models, Molecular Structure-Activity Relationship Tubulin Zebrafish Zebrafish Proteins Structural insights into HDAC6 tubulin deacetylation and its selective inhibition. http://purl.org/coar/resource_type/c_6501