McConnell D J, Searcy D G, Sutcliffe J G
Nucleic Acids Res. 1978 Jun;5(6):1729-39. doi: 10.1093/nar/5.6.1729.
A type II restriction enzyme (Tha I) has been isolated from the thermophilic mycoplasma Thermoplasma acidophilum. A new method of general application was used to determine the DNA sequence cleaved by the enzyme. Tha I cuts DNA in the centre of the sequence CGCG. Single-stranded DNA is not a substrate. Tha I does not cut T. acidophilum DNA which is presumably modified. This is the first description of a restriction enzyme from a mycoplasma. Because Tha I is easily prepared in large amounts of approximately 10(5) units per gram of cells, it will be a valuable addition to the battery of restriction enzymes used in studies of DNA sequences. It is active at high temperatures and may therefore be useful for special purposes requiring more extreme conditions.
已从嗜热支原体嗜酸嗜热栖热菌中分离出II型限制酶（Tha I）。采用一种通用的新方法来确定该酶切割的DNA序列。Tha I在序列CGCG的中心切割DNA。单链DNA不是其底物。Tha I不切割可能已被修饰的嗜酸嗜热栖热菌DNA。这是对支原体来源的限制酶的首次描述。由于Tha I易于大量制备，每克细胞约有10⁵单位，它将成为用于DNA序列研究的一系列限制酶中的宝贵补充。它在高温下具有活性，因此可能对需要更极端条件的特殊用途有用。
