Kinase Family Bub
Kinase Classification: Group Other: Family Bub
Bub1 is an essential mitotic checkpoint kinase in most eukaryotes.
Evolution
Bub1 is found in most eukaryotes, and has a key role in cell cycle
Domain Structure
The ancestral state of Bub1 has an N-terminal KEN box, followed by TPR repeats and a GLEBS domain, and finally a C-terminal kinase domain. In at least 9 different evolutionary lineages, Bub1 has duplicated, with one copy typically losing the kinase domain (often called MAD3) and the other losing the KEN box [1]. In vertebrates, the MAD3 homolog is BUB1, and retains the kinase domain, though it appears to be a pseudokinase.
Function
Bub1 is a mitotic checkpoint kinase with functions in the establishment of the mitotic spindle assembly checkpoint (SAC) and chromosome congression (see Wikipedia).