Fig. 2

TUBG1 Mutations in Individuals with Refractory Early-Onset Epilepsy. Top: crystal structure of γ-tubulin. Dimeric γ-tubulin is shown as ribbons, and the GTP bound molecule is shown as stick (PDB ID: 3CB2 [13]). Mutated residues, identified in this study (green) are shown. Right: close-up view of the GTP-binding pocket. Left: close-up view of the γ-γ dimer interface. GTP molecule and interacting residues are shown in stick representation, the Mg²⁺ ion as a sphere, and hydrogen bonds as green dashed lines (PDB ID: 1Z5V [7]). Images were generated using PyMOL. Bottom: partial sequence alignment of TUBG1 orthologs and different human tubulin proteins surrounding the Asp68 mutated residue. Identical residues across all proteins are shown in black, and residues identical to the human TUBG1 are in gray. GenBank accession numbers are as follows: Homo sapiens, NP_001061.2; Mus musculus, NP_598785.1; Gallus gallus, XP_015155127.1; Xenopus tropicalis, NP_001072509.1; Dario rerio, NP_957202.1; Caenorhabditis elegans, NP_499131.1; Arabidopsis thaliana, NP_191724.1; human TUBA1A, NP_001257328.1; human TUBA8, NP_061816.1; human TUBB, NP_001280141.1; human TUBB2A, NP_001060.1; human TUBB2B, NP_821080.1; TUBB3, NP_006077.2; and human TUBB4A, NP_001276052.1. Sequences were aligned with CLUSTAL Omega.32 Asterisks indicate positions with a single fully conserved residue, colons indicate conservation between groups with strongly similar properties, and periods indicate conservation between groups with weakly similar properties