Müller M, Wurtz M, Kellenberger E, Aebi U
M. E. Müller-Institute for High-Resolution Electron Microscopy, Biocenter, University of Basel, Switzerland.
J Struct Biol. 1991 Feb;106(1):17-30. doi: 10.1016/1047-8477(91)90059-6.
A double-stranded DNA containing, T even-like, Escherichia coli bacteriophage, called MM, has been isolated from the local sewage and purified by polyethylene glycol precipitation followed by banding on a cesium chloride three-step gradient. It yields a burst size of 75 particles per infected cell, and has an adsorption coefficient of 3.3 x 10(-10) cm3/min and a latent period of 45 min. Electron microscopy of phage MM reveals an isometric icosahedral head, 92 nm long and 81 nm wide, and a 112-nm-long contractile tail with six pairs of 40-nm-long fibers attached to its baseplate. Phage MM appears similar to E. coli phage T4 or Salmonella phage O1. The density of phage MM in cesium chloride is 1.515 g/ml, and its total mass is 144 MDa. Gel electrophoresis of purified MM capsids displays two major capsid proteins in approximately equimolar amounts and with apparent molecular masses of 38 and 15 kDa. Similarly, purified MM tails yield two major polypeptides with apparent molecular masses of 55 and 16 kDa, most likely representing the major tail sheath and tail tube polypeptides. Its double-stranded DNA has a G-C content of 50%, a length of 131 kilobases (kb), and a mass of 89 MDa.
一种含有双链DNA、类似T偶数的大肠杆菌噬菌体，称为MM，已从当地污水中分离出来，并通过聚乙二醇沉淀，随后在氯化铯三步梯度上进行密度梯度离心纯化。它每个感染细胞产生75个噬菌体颗粒的爆发量，吸附系数为3.3×10⁻¹⁰ cm³/分钟，潜伏期为45分钟。噬菌体MM的电子显微镜观察显示，其头部为等轴二十面体，长92纳米，宽81纳米，尾部为112纳米长的收缩尾，有六对40纳米长的纤维附着在基板上。噬菌体MM看起来与大肠杆菌噬菌体T4或沙门氏菌噬菌体O1相似。噬菌体MM在氯化铯中的密度为1.515克/毫升，总质量为144兆道尔顿。纯化的MM衣壳的凝胶电泳显示出两种主要衣壳蛋白，含量大致相等，表观分子量分别为38和15千道尔顿。同样，纯化的MM尾部产生两种主要多肽，表观分子量分别为55和16千道尔顿，最有可能分别代表主要的尾鞘和尾管多肽。其双链DNA的G-C含量为50%，长度为131千碱基（kb），质量为89兆道尔顿。
