Zou N, Park K, Dybvig K
Department of Microbiology, University of Alabama at Birmingham 35294, USA.
Plasmid. 1995 Jan;33(1):41-9. doi: 10.1006/plas.1995.1005.
Mycoplasma virus P1 is a tailed, polyhedral virus isolated from Mycoplasma pulmonis. To characterize the P1 genome, stocks of virus were prepared free of host cell nucleic acids. A single DNA species of 11.3 kb that was shown by plaque hybridization to be of P1 origin was extracted from the virus. Efficient isolation of P1 DNA required digestion with proteolytic enzymes prior to phenol extraction. Although P1 DNA was double-stranded and linear following such treatment, it was resistant to digestion with the 5'-specific lambda exonuclease. Electron microscopic analysis indicated that globular material is complexed to the ends of P1 DNA. The globular material was not observed on protease-treated P1 DNA molecules, suggesting that it is composed of protein. Removal of the putative terminal protein by chemical treatment allowed the cloning of the P1 DNA ends, and nucleotide sequence analysis revealed that these ends contain a 350-bp inverted terminal repeat.
支原体病毒P1是一种从肺支原体中分离出的有尾多面体病毒。为了表征P1基因组，制备了不含宿主细胞核酸的病毒储备液。从病毒中提取出一种11.3 kb的单一DNA片段，通过噬菌斑杂交证明其来源于P1。高效分离P1 DNA需要在酚提取之前用蛋白水解酶消化。尽管经过这样的处理后P1 DNA是双链线性的，但它对5'-特异性λ外切核酸酶的消化具有抗性。电子显微镜分析表明，球状物质与P1 DNA的末端结合。在蛋白酶处理的P1 DNA分子上未观察到球状物质，这表明它由蛋白质组成。通过化学处理去除假定的末端蛋白后，实现了P1 DNA末端的克隆，核苷酸序列分析表明这些末端包含一个350 bp的反向末端重复序列。
