This is the C-terminal domain found in components of the gamma-tubulin complex proteins (GCPs). Family members include spindle pole body (SBP) components such as Spc97 and Spc98 which function as the microtubule-organizing center in yeast [1]. Furthermore, family members such as human GCP4 (Gamma-tubulin complex component 4) have been structurally elucidated Swiss:Q9UGJ1 . Structure-based sequence analysis revealed the existence of an exposed surface area conserved in all human GCPs and in GCP4 orthologs. This area is located in the C-terminal domain of GCP4, which was confirmed in vitro to bind directly to gamma-tubulin. Sequence alignment of human GCPs based on the GCP4 structure helped delineate conserved regions in the N- and C-terminal domains [2].

1: Characterization and reconstitution of Drosophila gamma-tubulin ring complex subunits. Gunawardane RN, Martin OC, Cao K, Zhang L, Dej K, Iwamatsu A, Zheng Y; J Cell Biol. 2000;151:1513-1524. PMID:11134079

2: Crystal structure of gamma-tubulin complex protein GCP4 provides insight into microtubule nucleation. Guillet V, Knibiehler M, Gregory-Pauron L, Remy MH, Chemin C, Raynaud-Messina B, Bon C, Kollman JM, Agard DA, Merdes A, Mourey L; Nat Struct Mol Biol. 2011;18:915-919. PMID:21725292