Comparison of the genome for phylogenetically related bacteriophages ϕKZ and EL of Pseudomonas aeruginosa: Evolutionary aspects and minimal genome size

Abstract

Bacteriophages of the family Myoviridae represent one of the most widespread domains of the biosphere substantially affecting the ecological balance of microorganisms. Interestingly, sequence analysis of genomic DNAs of large bacteriophages revealed many genes coding for proteins with unknown functions. A new approach is proposed to improve the functional identification of genes. This approach is based on comparing the genome sequence for phylogenetically and morphologically related phages showing no considerable homology at the level of genomic DNA. It is assumed that gene functions essential for the development of phages of a given family are conserved and that the corresponding genes code for similar orthologous proteins even when lacking sequence homology. The genome was sequenced and compared for two Pseudomonas aeruginosa giant bacteriophages, ϕ KZ and EL, which belong to a group of ϕ KZ-related phages. A substantial difference in genome organization was observed, suggesting specific features of phage evolution. In addition, the problem of the minimal genome of the superfamily is discussed on the basis of the difference in size and structure between the ϕ KZ and EL genomes.

Modular Approach to Select Bacteriophages Targeting Pseudomonas aeruginosa for Their Application to Children Suffering With Cystic Fibrosis

“…The phiKZ-like group of giant phages infecting P. aeruginosa includes several species and are of interest not only because of their use in a therapeutic setting, but also as a unique model for the study of phage evolution and specific packaging of the genomic DNA ( Burkal’tseva et al, 2002 ; Mesyanzhinov et al, 2002 ; Krylov et al, 2003 , 2004 , 2005 , 2011 ; Hertveldt et al, 2005 ; Shaburova et al, 2008 ; Pleteneva et al, 2010 ; Sokolova et al, 2014 ). This group of Myoviridae phages includes several phage species that exhibit common properties of the type member phiKZ (particle size and morphology, the presence of an inner body in the capsid, and a specific packaging mechanism of phage genomic DNA).…”