Extended Data Fig. 6: Structure of related TTLL enzymes and TTLL6 with tetrahedral intermediate analogs.
From: Structural basis for polyglutamate chain initiation and elongation by TTLL family enzymes
a, Cartoon representation of previously determined crystal structures of related TTLL family of enzymes. Left to right: tubulin tyrosine ligase TTL (pdb code:4IHJ), closely related glutamylase TTLL7 (pdb code:4YLR), and the glycylase TTLL3 (pdb code:5VLQ). Nucleotides are shown as stick model. Dotted lines represent regions of the polypeptide chain that are disordered in the crystal structure (b) Mechanism for inhibitor phosphorylation (c) Active site showing the |Fo|-|Fc| density (prior to modeling the γ-elongation analog) contoured at 4σ (blue). d, Active site showing the |Fo|-|Fc| density (prior to modeling the initiation analog) contoured at 3σ (blue). e, Electrostatic surface of the TTLL6 active site showing the high electropositive character and the positively charged groove adjacent to the acceptor glutamate binding site. α-elongation analog shown as a stick model. The donor glutamate, transferred phosphate and acceptor glutamate of the α-elongation analog are colored pink, orange and cyan, respectively. Conserved residues are labeled on the molecular surface.
