Bickel S E, Wyman D W, Miyazaki W Y, Moore D P, Orr-Weaver T L
Whitehead Institute for Biomedical Research, Massachusetts Institute of Technology, Cambridge, 02142, USA.
EMBO J. 1996 Mar 15;15(6):1451-9.
Attachment between the sister chromatids is required for proper chromosome segregation in meiosis and mitosis, but its molecular basis is not understood. Mutations in the Drosophila ord gene result in premature sister chromatid separation in meiosis, indicating that the product of this gene is necessary for sister chromatid cohesion. We isolated the ord gene and found that it encodes a novel 55 kDa protein. Some of the ord mutations exhibit unusual complementation properties, termed negative complementation, in which particular alleles poison the activity of another allele. Negative complementation predicts that protein-protein interactions are critical for ORD function. The position and nature of these unusual ord mutations demonstrate that the C-terminal half of ORD is essential for sister chromatid cohesion and suggest that it mediates protein binding.
姐妹染色单体之间的连接对于减数分裂和有丝分裂中染色体的正确分离是必需的，但其分子基础尚不清楚。果蝇ord基因的突变会导致减数分裂中姐妹染色单体过早分离，表明该基因的产物对于姐妹染色单体的黏连是必需的。我们分离出了ord基因，发现它编码一种新的55 kDa蛋白质。一些ord突变表现出不同寻常的互补特性，称为负互补，即特定的等位基因会损害另一个等位基因的活性。负互补预示着蛋白质-蛋白质相互作用对于ORD功能至关重要。这些不同寻常的ord突变的位置和性质表明，ORD的C端一半对于姐妹染色单体的黏连至关重要，并表明它介导蛋白质结合。
