RETINOBLASTOMA SUSCEPTIBILITY GENES CONTAIN 5' SEQUENCES WITH A HIGH PROPENSITY TO FORM GUANINE-TETRAD STRUCTURES
RETINOBLASTOMA SUSCEPTIBILITY GENES CONTAIN 5' SEQUENCES WITH A HIGH PROPENSITY TO FORM GUANINE-TETRAD STRUCTURES
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DOI：
10.1093/nar/20.1.49
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发表时间：
1992-01-11
影响因子：
14.9
通讯作者：
LILLEY, DMJ
中科院分区：
文献类型：
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作者：
MURCHIE, AIH;LILLEY, DMJ
视网膜母细胞瘤易感基因在其5'端含有显著的寡鸟嘌呤序列。 具有这些序列的寡核苷酸在钠离子存在下经历复合物形成，其中存在四条链的缔合。 如果鸟嘌呤被7-脱氮鸟嘌呤取代，这种结构的形成被完全阻止，表明鸟嘌呤N7在复合物形成中的重要性。 复合物的形成导致保护鸟嘌呤N7对甲基化硫酸二甲酯，但胸腺嘧啶碱基之间的寡鸟嘌呤块反应四氧化锇。 对寡鸟嘌呤阻断的5'侧的S1核酸酶也有一定的敏感性。 结果表明，小鼠和人类视网膜母细胞瘤易感基因的富含G的区域具有经历在免疫球蛋白开关区域中所证明的那种四链体形成的倾向。
Retinoblastoma susceptibility genes contain significant runs of oligoguanine at their 5' ends. Oligonucleotides having these sequences underwent complex formation in the presence of sodium ions, in which there was association of four strands. Formation of this structure was completely prevented if guanine was replaced by 7-deazaguanine, indicating the importance of guanine N7 in the formation of the complex. Complex formation lead to protection of guanine N7 against methylation by dimethyl sulphate, but thymine bases located between oligoguanine blocks were reactive to osmium tetroxide. There was also some sensitivity to S1 nuclease to the 5' side of the oligoguanine block. The results show that the G-rich regions of the mouse and human retinoblastoma susceptibility genes have a propensity to undergo tetraplex formation of the kind demonstrated in the immunoglobulin switch region.