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Basic Methods in Cellular and Molecular Biology
Restriction Enzymes: DNA Cutting Guide
Description
Restriction enzymes are bacterial proteins that cut DNA at specific sequences. They are also called endonucleases. In bacteria, these enzymes help defend against bacteriophages, which are viruses that infect bacteria. The bacterial DNA is protected because methyl groups are added, so the restriction enzymes cut the invading ...
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Transcript
限制性酶或称限制性内切酶，在分子生物学中的应用多种多样。这些酶识别并切开DNA上被称为限制性酶切位点的某个特定序列。接下的视频将为您介绍这些神奇的分子，并演示如何准备限制性酶消化。
限制性酶究竟从何而来？这些酶被发现是细菌适应产生的一种防御机制，用来抵御被称为噬菌体的病毒。由于细菌本身的DNA上这些酶切位点被添加了甲基化集团，限制性酶只能识别并消化病毒的DNA, 从而有效防止了感染。
限制性酶的名字有些奇怪，象HindIII, NotI, EcoRI,还有BamHI。限制性酶名字的前三个字母是代表酶提取的生物来源。例如，EcoRI是从大肠杆菌E.coli中分离出来。...
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