On the Evolution of the Terminal Redundancies of Klebsiella Phage No. 11 and of Coliphages T3 and T7

Abstract

SUMMARYThe phylogenetic relationship between Klebsiella phage No. 11 and the classical coilphages T7 and T3, postulated in a previous study, was investigated at the nucleotide level by sequencing the termini of phage No. 11 DNA. This DNA was found to have a terminal redundancy of 181 base pairs. Comparison of the terminal sequences of T7, T3 and No. 11 DNA suggests that the terminal redundancies of the three phages contain different expansions and variations of the short "founder sequence' 5' TTAACCTTGGG 3' of a common ancestor.In a previous study (Korsten et al., 1979) we reported evidence that the capsule-specific Klebsiella phage No. 11 (henceforth called K 11) is distantly related to the classical coliphages T3 and T7. This evidence was based mainly on the fact that phage K11, like T3 and T7, codes for an early protein of molecular weight about 100000 which shows an RNA polymerase activity specific for promoters located on the phage genome and not found on the DNA of the host. However, the template specificity of the phage K11 polymerase was totally different from that of T3 or T7: the RNA polymerases of these phages did not transcribe phage K11 DNA to any extent, and vice versa. (This is in contrast to the 20 to 50% heterologous transcriptional activity found upon comparing the RNA polymerases ofT3 and T7.) No compelling evidence for a phylogenetic common origin of phages K11 on the one hand, and T3 and T7 on the other, was provided by other criteria, since the first showed no serological crossreactions with the latter and K11 DNA did not efficiently form heteroduplexes with DNA ofT3 or T7. Also, a comparison of the electrophoretic patterns of Kll-coded intracellular proteins with those of T7 revealed marked differences in the molecular weights of most proteins; thus, only a few of these could be considered obviously homologous (Korsten et al., 1979). We undertook the present study with the aim of clarifying, at the nucleotide level, the putative phylogenetic relationship of phage K 11 with phages T3 and T7 by sequencing the termini of K I 1 DNA. Our results show that this phage has a characteristic terminal redundancy (TR) which we have compared to the known sequences of the TR of T7 (Moffat et al

Two Groups of Capsule-specific Coliphages Coding for RNA Polymerases with New Promoter Specificities

“…transcription of the DNA of one phage by the RNA polymerase of another), there was a phylogenetic relationship between T7, K11 and Villi. In the meantime Dietz (1985) and Dietz et al (1985) have confirmed this hypothesis for T7 and K11 by means of base sequence analysis of some segments of K11 DNA and comparison to the corresponding sequences of T7 DNA, as determined by , and to the DNA sequences of T3 (which is related to T7) as determined by Fujisawa & Sugimoto (1983) and by McAllister et al (1983). However, so far no capsule-specific Escherichia coli phages have been shown to be related to T7.…”

Mechanism of inhibition of bacteriophage T7 RNA polymerase by T7 lysozyme

“…The vertical bar after nucleotide 160 indicates the right end of mature T7 DNA. Sequences from the corresponding regions of the DNAs of the related phages T3 and K11 (Fujisawa & Sugimoto, 1983;Dietz et al, 1985) are aligned with the T7 sequence around the mature right end. Every position where the three sequences have the same base is indicated by dots.…”

Characterization of Extended-Host-Range Pseudo-T-Even Bacteriophage Kpp95 Isolated on Klebsiella pneumoniae

“…In these positive cases, plating efficiencies were similar when the same batches of the phage lysate were used for different host strains. Acinetobacter baumannii (10), Enterobacter cloacae (12), E. coli (14), Proteus mirabilis (14), and Pseudomonas aeruginosa (7), with the total numbers of strains tested in parentheses, were found to be resistant to Kpp95.…”

“…Therefore, it is generally accepted that the isolation of host range mutant phages and the use of cocktails containing several phages in one preparation should be necessary to reduce the probability of resistance development and to cover a breadth of host ranges (31,40). The lytic phage Kpp95, able to cause rapid and clear lysis of many K. pneumoniae strains, is worthy of development into a component of a therapeutic cocktail, maybe in conjunction with K. pneumoniae phages, which have previously been characterized as virulent (4,10,14,43,51,55), or with antibiotics. Furthermore, with a broad host range, a therapeutic agent based on Kpp95 has the potential to treat coinfections by E. agglomerans, K. oxytoca, and S. marcescens.…”