Data for: Mechanistic insights into TTLL11 polyglutamylase-mediated primary tubulin chain elongation

Microtubules (MTs) undergo diverse posttranslational modifications that regulate their structural and functional properties. Among these, polyglutamylation—a dominant and conserved modification targeting unstructured tubulin C-terminal tails—plays a pivotal role in defining the tubulin code. Here, we describe a mechanism by which tubulin tyrosine ligase–like 11 (TTLL11) expands and diversifies the code. Cryo–electron microscopy revealed a unique bipartite MT recognition strategy wherein TTLL11 binding and catalytic domains engage adjacent MT protofilaments. Biochemical and cellular assays identified previously uncharacterized polyglutamylation patterns, showing that TTLL11 directly extends the primary polypeptide chains of α-and β-tubulin in vitro, challenging the prevailing paradigms emphasizing lateral branching. Moreover, cell-based and in vivo data suggest a cross-talk between polyglutamylation and the detyrosination/tyrosination cycle likely linked to the TTLL11-mediated elongation..., , # Data for: Mechanistic insights into TTLL11 polyglutamylase-mediated primary tubulin chain elongation

Dataset DOI: [10.5061/dryad.6djh9w1dj](10.5061/dryad.6djh9w1dj)

## Description of the data and file structure

All data were acquired to describe the structure and functions of TTLL11 polyglutamylase. Many methods were used, including cryo-EM, mass spectrometry, TIRF microscopy, and cell-based assays. 

### Files and variables

#### File: TTLL11_MT_complex_structure_(1).zip

**Description:** model of the TTLL11/microtubules complex and the deposition protocol from the RCSB database

#### File: cryosparc_P35_J257_006_volume_map_hancer_highRes.mrc

**Description:** map of the TTLL11/microtubules complex from cryo-EM

#### File: 18O.zip

**Description:** MS data of glutamylation by TTLL11 and 18O labeled glutamate

#### File: TIRF_TTLL11_variants.zip

**Description:** TIRF microscopy image of TTLL11 variants binding to microtubules

#### File: fragmentation_data_hMTs.zip

**Description:...,