Middle HEAT-repeat binding domain found in Schizosaccharomyces pombe cohesin subunit rad21 (SpRad21p) and similar proteins
SpRad21p, also called double-strand-break (DSB) repair protein rad21, or SCC1 homolog, is a cleavable component of the cohesin complex, involved in chromosome cohesion during the cell cycle. The cohesin complex is required for the cohesion of sister chromatids after DNA replication. It apparently forms a large proteinaceous ring within which sister chromatids can be trapped. At the metaphase-anaphase transition, SpRad21p is cleaved by cut1 and dissociates from chromatin, allowing sister chromatids to segregate. It is also involved in the DNA DSB repair system. This model corresponds to a small region in the middle of SpRad21p that shows high sequence similarity with the HEAT-repeat binding domain found in both Saccharomyces cerevisiae sister chromatid cohesion protein 1 (ScScc1p) and Homo sapiens nuclear matrix protein 1 (NXP-1), which consists of short helices and two long extended segments.
Jiyao W et al.(2023). "The conserved domain database in 2023.",