Topology David Shiuan Department of Life Science Institute of Biotechnology Interdisciplinary Program of Bioinformatics National Dong Hwa University
拓 樸 學 (Topology) 拓樸學(Topology)是近代數學的一支,拓樸學研究的是一些圖型經類似拉長或壓縮後皆不變的幾何性質(橡皮幾何學) Topology (Greek topos, "place," and logos, "study") is a branch of mathematics that is an extension of geometry. Topology begins with a consideration of the nature of space, investigating both its fine structure and its global structure. Topology builds on set theory, considering both sets of points and families of sets.
Homotopy
Knot Theory
Molecular Knot
DNA Topology DNA在結構上主要有三種拓樸構變化：超螺旋（supercoiling） 紐結（knotting） 連鎖（catenation） Topology能夠使DNA在不進行DNA複製與轉錄的時候，維持其緊密性。反之在轉錄或複製過程中，這些拓撲構型將會阻礙反應
DNA Topology Circular DNA Supercoiling
Topoisomerase 拓樸異構酶 王卓 Type-I topoisomerase 可將雙股螺旋DNA包覆，以破壞phosphodiester bond的方式切斷其中一股DNA，產生一個小缺口，此時另一股完整的DNA將會穿過此缺口，之後重新黏合。Topoisomerase -I 與 -III Type-II topoisomerase 可將雙股螺旋DNA上的兩股DNA皆切斷，產生缺口，使另一條雙股螺旋能夠穿過此缺口，之後再重新黏合。topoisomerase-IIα與IIβ
Topo-II Catalyzes the catenation and decatenation