Shaburova O V, Krylov S V, Veĭko V P, Pleteneva E A, Burkal'tseva M V, Miroshnokov K A, Kornelissen A, Lavogne R, Sykilinda N N, Kadykov V A, Mesianzhinov V V, Volckaert G, Krylov V N
Genetika. 2009 Feb;45(2):185-95.
Comparison of Pseudomonas putida group of phages attributed to five species (af, phi15, phi27, phi2F, and pf16) with their common property of halo-formation (formation of lightening zones) around phage plaques was conducted. The halo around phage plaques appears as a result of reduction or disappearance of bacterial polysaccharide capsules. The concentration of viable bacteria remains unchanged within the halo. A comparison of specificities of halo-formation products from various phages was conducted by a simple method. These products were shown to be highly specific and inactive on other species of pseudomonads. Phage-resistant P. putida mutants scored with respect to various phages, which lost phage adsorption ability, were tolerant to the effect of halo-formation products in most cases. Apparently, the capsular polysaccharides, which serve as a substrate for depolymerases and are the primary phage receptors, may be often lost. Results of partial sequencing of the af phage genome revealed an open reading frame that encodes the enzyme transglycosylase similar rather to transglycosylases of oligotrophic bacteria belonging to different species than to lysozymes of other phages. Possibly, it is a polyfunctional enzyme combining functions of lysozyme and an enzyme that executes the penetration of phage particle across extracellular slime and capsule.
对属于五个物种(af、phi15、phi27、phi2F和pf16)的恶臭假单胞菌噬菌体群进行了比较,这些噬菌体具有在噬菌斑周围形成晕圈(闪电区形成)的共同特性。噬菌斑周围的晕圈是细菌多糖荚膜减少或消失的结果。晕圈内活细菌的浓度保持不变。通过一种简单的方法对来自各种噬菌体的晕圈形成产物的特异性进行了比较。这些产物显示出高度特异性,对其他假单胞菌物种无活性。针对各种噬菌体对丧失噬菌体吸附能力的噬菌体抗性恶臭假单胞菌突变体进行了评分,在大多数情况下,这些突变体对晕圈形成产物的作用具有耐受性。显然,作为解聚酶底物且是主要噬菌体受体的荚膜多糖可能经常丢失。af噬菌体基因组的部分测序结果揭示了一个开放阅读框,该框编码的转糖基酶与不同物种的贫营养细菌的转糖基酶相似,而与其他噬菌体的溶菌酶不同。可能它是一种多功能酶,兼具溶菌酶和使噬菌体颗粒穿过细胞外粘液和荚膜的酶的功能。