title: Comparative genomics and transcriptional analysis of prophages identified in the genomes of Lactobacillus gasseri, Lactobacillus salivarius, and Lactobacillus casei.
abstract: Lactobacillus gasseri ATCC 33323, Lactobacillus salivarius subsp. salivarius UCC 118, and Lactobacillus casei ATCC 334 contain one (LgaI), four (Sal1, Sal2, Sal3, Sal4), and one (Lca1) distinguishable prophage sequences, respectively. Sequence analysis revealed that LgaI, Lca1, Sal1, and Sal2 prophages belong to the group of Sfi11-like pac site and cos site Siphoviridae, respectively. Phylogenetic investigation of these newly described prophage sequences revealed that they have not followed an evolutionary development similar to that of their bacterial hosts and that they show a high degree of diversity, even within a species. The attachment sites were determined for all these prophage elements; LgaI as well as Sal1 integrates in tRNA genes, while prophage Sal2 integrates in a predicted arginino-succinate lyase-encoding gene. In contrast, Lca1 and the Sal3 and Sal4 prophage remnants are integrated in noncoding regions in the L. casei ATCC 334 and L. salivarius UCC 118 genomes. Northern analysis showed that large parts of the prophage genomes are transcriptionally silent and that transcription is limited to genome segments located near the attachment site. Finally, pulsed-field gel electrophoresis followed by Southern blot hybridization with specific prophage probes indicates that these prophage sequences are narrowly distributed within lactobacilli.
authors: Department of Genetics, Anthropology and Evolution, University of Parma, Parco Area delle Scienze 11/a, 43100 Parma, Italy. marco.ventura@unipr.it
authors: Marco
authors: M
authors: Ventura
authors: Carlos
authors: C
authors: Canchaya
authors: Valentina
authors: V
authors: Bernini
authors: Eric
authors: E
authors: Altermann
authors: Rodolphe
authors: R
authors: Barrangou
authors: Stephen
authors: S
authors: McGrath
authors: Marcus J
authors: MJ
authors: Claesson
authors: Yin
authors: Y
authors: Li
authors: Sinead
authors: S
authors: Leahy
authors: Carey D
authors: CD
authors: Walker
authors: Ralf
authors: R
authors: Zink
authors: Erasmo
authors: E
authors: Neviani
authors: Jim
authors: J
authors: Steele
authors: Jeff
authors: J
authors: Broadbent
authors: Todd R
authors: TR
authors: Klaenhammer
authors: Gerald F
authors: GF
authors: Fitzgerald
authors: Paul W
authors: PW
authors: O'toole
authors: Douwe
authors: D
authors: van Sinderen