Laurent B C, Treich I, Carlson M
Department of Genetics and Development, Columbia University College of Physicians and Surgeons, New York, New York 10032.
Genes Dev. 1993 Apr;7(4):583-91. doi: 10.1101/gad.7.4.583.
The yeast SNF2 (SWI2) protein functions with SNF5, SNF6, SWI1, and SWI3 in the transcriptional activation of many differently regulated genes. These proteins appear to facilitate activation by gene-specific regulatory proteins. SNF2 is highly conserved among eukaryotes and defines a family of proteins with similarity to helicases and nucleic acid-dependent NTPases. Here, we present genetic and biochemical evidence that SNF2 has DNA-stimulated ATPase activity. Mutations in the nucleoside triphosphate (NTP)-binding motif and other conserved motifs impair SNF2 function. Swapping experiments with another member of this family indicate that the helicase-related domains are functionally interchangeable. Finally, bacterially expressed SNF2 protein has ATPase activity that is stimulated by double-stranded DNA, and mutation of the NTP-binding site abolishes this activity. Deletion analysis shows that the helicase-like region of SNF2 is necessary, but not sufficient, for transcriptional activation.
酵母SNF2（SWI2）蛋白与SNF5、SNF6、SWI1和SWI3共同作用，参与许多不同调控基因的转录激活。这些蛋白似乎通过基因特异性调控蛋白促进激活过程。SNF2在真核生物中高度保守，定义了一类与解旋酶和核酸依赖性NTP酶相似的蛋白质家族。在此，我们提供遗传和生化证据表明SNF2具有DNA刺激的ATP酶活性。核苷三磷酸（NTP）结合基序及其他保守基序中的突变会损害SNF2功能。与该家族另一个成员的交换实验表明，解旋酶相关结构域在功能上是可互换的。最后，细菌表达的SNF2蛋白具有由双链DNA刺激的ATP酶活性，NTP结合位点的突变会消除这种活性。缺失分析表明，SNF2的解旋酶样区域对于转录激活是必要的，但并不充分。
