Villanueva N, Salas M
J Virol. 1981 Apr;38(1):15-9. doi: 10.1128/JVI.38.1.15-19.1981.
Phage phi 29 particles produced under restrictive conditions by mutants in gene 12 have normal amounts of all of the structural proteins except the appendage protein, p12*, which is missing. These particles are not infective and do not adsorb to Bacillus subtilis cells. By in vitro complementation of 12- particles with extracts containing protein p12* or with purified protein p12*, the defective particles could bind the appendage protein and become infective and able to adsorb to bacteria. Therefore, the neck appendages of phage phi 29, formed by protein p12*, are involved in the interaction of the phage with the cell wall receptors. Protein p12*, purified in its native state, competed with wild-type phage for adsorption to bacteria. Also, protein p12* could displace adsorbed phage from bacteria. Since the displaced phage was infective, protein p12* does not seem to be modified after phage adsorption.
在限制条件下由基因12中的突变体产生的噬菌体φ29颗粒，除了缺失的附属蛋白p12外，所有结构蛋白的含量均正常。这些颗粒没有感染性，也不吸附到枯草芽孢杆菌细胞上。通过用含有蛋白p12的提取物或纯化的蛋白p12对12-颗粒进行体外互补，缺陷颗粒可以结合附属蛋白并变得具有感染性且能够吸附到细菌上。因此，由蛋白p12形成的噬菌体φ29的颈部附属物参与了噬菌体与细胞壁受体的相互作用。以天然状态纯化的蛋白p12与野生型噬菌体竞争吸附到细菌上。此外，蛋白p12可以将吸附的噬菌体从细菌上置换下来。由于被置换的噬菌体具有感染性，蛋白p12*在噬菌体吸附后似乎没有被修饰。
