Fission yeast has three kinetochore protein complexes. Two complexes, Sim4 and Ndc80-MIND-Spc7 (NMS), are constitutive components, whereas the third complex, DASH, is transiently associated with kinetochores only in mitosis and is required for precise chromosome segregation. The Sim4 complex functions as a loading dock for the DASH complex. Sim4 consists of a number of different proteins including Ftas 1-7 and Dad1. The equivalent higher eukaryotic protein is CENP-P. The centromere, which is the basic element of chromosome inheritance, is epigenetically determined in mammals. CENP-A, the centromere-specific histone H3 variant, assembles an array of nucleosomes and it is this that seems to be the prime candidate for specifying centromere identity. CENP-A nucleosomes directly recruit a proximal CENP-A nucleosome associated complex (NAC) comprised of CENP-M, CENP-N and CENP-T, CENP-U(50), CENP-C and CENP-H. Assembly of the CENP-A NAC at centromeres is dependent on CENP-M, CENP-N and CENP-T. Additionally, there are seven other subunits which make up the CENP-A-nucleosome distal (CAD) centromere, CENP-K, CENP-L, CENP-O, CENP-P, CENP-Q, CENP-R and CENP-S, also assembling on the CENP-A NAC.