DNA是生物體內記錄遺傳訊息的分子，並透過不同功能的蛋白質進行轉錄、修復、重組、複製等反應機制。當DNA要進行特定的生理反應時會和功能性蛋白質鍵結形成特殊的結構，若此蛋白質和DNA分子結合時能夠透過儀器分析其結構與數量，將能夠更完整的了解蛋白質在生物體內的反應機制。
本實驗主要利用掃描式探針顯微鏡(Scanning Probe Microscope，SPM)在次奈米(sub-nanometer)解析度中辨識DNA-蛋白質錯合物結構。並選用單股DNA M13 ss/fMet2WT與雙股DNA M13RF/G72作為蛋白質鍵結的模板和三種蛋白質作用，蛋白質的類型分別為Tth SSB、RecA、T7 endonuclease I，透過SPM檢測觀察在特定條件中的蛋白質-DNA錯合物特殊結構。
根據SPM影像辨識指出：Tth SSB和單股DNA作用能夠形成凝態結構、彎折結構與結點結構，Tth SSB和雙股DNA作用則形成結點結構。RecA和單股DNA作用能形成凝態結構、結點結構，RecA和雙股DNA作用則可形成結點結構。T7 endonuclease I和單股DNA作用可辨識髮夾結構並形成結點結構，T7 endonuclease I和雙股DNA作用可辨識十字結構。

DNA is a molecular record the genetic information in creature. Protein can combine with the DNA at specific structure to process translation、repair、recombination and replication reaction. The DNA-protein complexes conformation can be analyzed by microscopy to verify the different bio-reaction mechanisms.
In this experiment, Identification of spatial structures on DNA-Protein complexes image in sub-nano resolution by Scanning Probe Microscope (SPM). The single strand DNA and double strand DNA are react with Tth SSB、RecA and T7 endonuclease I. According to the SPM images, Tth SSB can formation of node、bending and condensed structures with ssDNA, and it can formation of node structure with dsDNA. RecA can formation of node、bending and condensed structure with ssDNA, and it can formation of node and filament structure with dsDNA. T7 endo I can identify the hair-pin structure on ssDNA and cruciform structure on dsDNA.

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