Lillehaug D, Lindqvist B, Birkeland N K
Laboratory of Microbial Gene Technology, Oslo, Norway.
Appl Environ Microbiol. 1991 Nov;57(11):3206-11. doi: 10.1128/aem.57.11.3206-3211.1991.
The temperate bacteriophage phiLC3, isolated from Lactococcus lactis subsp. cremoris, has an isometric head and a flexible tail containing 1 major protein and 8 minor proteins. Infection of a permissive L. lactis host strain yields a burst of about 50 phages per infected cell with a latent period of 60 min. A detailed restriction map of the phage chromosome was constructed by using 12 different restriction enzymes. The phage chromosome is a 33-kb linear double-stranded DNA molecule with unique cohesive ends and with a G + C content of 36.5%. Chemical sequencing of the DNA ends revealed 13-base 3' extended complementary single strands with a relatively high percentage of G + C. Pulsed-field gel electrophoretic analysis of DNA from a strain lysogenized with phiLC3 was used to localize the prophage to a 320-kb BamHI restriction endonuclease fragment from the host chromosomal DNA. This result indicates that lysogeny involves integration of the phage into the host chromosome. A spontaneous phiLC3 clear plaque mutant that was unable to give rise to lysogens was isolated.
从乳酸乳球菌乳脂亚种中分离出的温和噬菌体phiLC3，具有等轴状头部和一条柔性尾部，包含1种主要蛋白质和8种次要蛋白质。感染允许性乳酸乳球菌宿主菌株后，每个受感染细胞会产生约50个噬菌体的爆发量，潜伏期为60分钟。通过使用12种不同的限制酶构建了噬菌体染色体的详细限制图谱。噬菌体染色体是一个33 kb的线性双链DNA分子，具有独特的粘性末端，G + C含量为36.5%。对DNA末端的化学测序揭示了13个碱基的3'延伸互补单链，其中G + C的比例相对较高。对用phiLC3溶源化菌株的DNA进行脉冲场凝胶电泳分析，以将原噬菌体定位到宿主染色体DNA的一个320 kb的BamHI限制性内切酶片段上。这一结果表明溶原作用涉及噬菌体整合到宿主染色体中。分离出了一个自发的phiLC3清亮噬菌斑突变体，它无法产生溶源菌。
