Component of the SKA1 complex, a microtubule-binding subcomplex of the outer kinetochore that is essential for proper chromosome segregation (PubMed:17093495, PubMed:19289083, PubMed:23085020). Required for timely anaphase onset during mitosis, when chromosomes undergo bipolar attachment on spindle microtubules leading to silencing of the spindle checkpoint (PubMed:17093495). The SKA1 complex is a direct component of the kinetochore-microtubule interface and directly associates with microtubules as oligomeric assemblies (PubMed:19289083). The complex facilitates the processive movement of microspheres along a microtubule in a depolymerization-coupled manner (PubMed:19289083). Affinity for microtubules is synergistically enhanced in the presence of the ndc-80 complex and may allow the ndc-80 complex to track depolymerizing microtubules (PubMed:23085020). In the complex, it mediates the interaction with microtubules (PubMed:19289083, PubMed:23085020). Component of the SKA1 complex, composed of SKA1, SKA2 and SKA3 (PubMed:17093495). Forms a heterodimer with SKA2; the heterodimer interacting with SKA3 (PubMed:17093495, PubMed:19289083, PubMed:23085020). The core SKA1 complex is composed of 2 SKA1-SKA2 heterodimers, each heterodimer interacting with a molecule of the SKA3 homodimer (PubMed:19289083). The core SKA1 complex associates with microtubules and forms oligomeric assemblies (PubMed:17093495, PubMed:19289083). Interacts with microtubules; the interaction is direct (PubMed:19289083, PubMed:23085020). Interacts with SKA2 (PubMed:19289083). Interacts with SKA3 (PubMed:19289083, PubMed:23085020). Localizes to the outer kinetochore and spindle microtubules during mitosis in a NDC80 complex-dependent manner (PubMed:17093495). Localizes to both the mitotic spindle and kinetochore-associated proteins (PubMed:17093495). Associates with kinetochores following microtubule attachment from prometaphase, through mid-anaphase and then vanishes in telophase (PubMed:17093495). Belongs to the SKA1 family.