title: The genomes and comparative genomics of Lactobacillus delbrueckii phages.
abstract: Lactobacillus delbrueckii phages are a great source of genetic diversity. Here, the genome sequences of Lb. delbrueckii phages LL-Ku, c5 and JCL1032 were analyzed in detail, and the genetic diversity of Lb. delbrueckii phages belonging to different taxonomic groups was explored. The lytic isometric group b phages LL-Ku (31,080 bp) and c5 (31,841 bp) showed a minimum nucleotide sequence identity of 90% over about three-fourths of their genomes. The genomic locations of their lysis modules were unique, and the genomes featured several putative overlapping transcription units of genes. LL-Ku and c5 virions displayed peptidoglycan hydrolytic activity associated with a ~36-kDa protein similar in size to the endolysin. Unexpectedly, the 49,433-bp genome of the prolate phage JCL1032 (temperate, group c) revealed a conserved gene order within its structural genes. Lb. delbrueckii phages representing groups a (a phage LL-H), b and c possessed only limited protein sequence homology. Genomic comparison of LL-Ku and c5 suggested that diversification of Lb. delbrueckii phages is mainly due to insertions, deletions and recombination. For the first time, the complete genome sequences of group b and c Lb. delbrueckii phages are reported.
authors.affiliation: Division of Genetics, Department of Biology, University of Oulu, P.O. Box 3000, 90014, Oulu, Finland. katja.riipinen@oulu.fi
authors.forename: Katja-Anneli
authors.initials: KA
authors.lastname: Riipinen
authors.forename: Päivi
authors.initials: P
authors.lastname: Forsman
authors.forename: Tapani
authors.initials: T
authors.lastname: Alatossava
mesh_terms: D001435:Bacteriophages / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification* / Q000502:physiology; D016679:Genome, Viral; D023281:Genomics; D058507:Host Specificity; D048668:Lactobacillus delbrueckii / Q000821:virology*; D008969:Molecular Sequence Data; D010802:Phylogeny