title: Transposition in Lactobacillus sake and its abolition of lactocin S production by insertion of IS1163, a new member of the IS3 family.
abstract: This report presents the nucleotide sequence and insertional activity of IS1163, which is a new member of the IS3 family of transposable elements. Analysis of spontaneous mutants of the lactocin S-producing Lactobacillus sake strain L45 show that the bacteriocin-negative phenotype is due to either loss of the producer plasmid or the insertion of IS1163 into the lactocin S operon (las operon). The data further show that insertional inactivation of the lactocin S operon is the result of a transposition event involving a chromosomally located donor copy of IS1163. Although the insertions described are clustered within a 250-bp region of the las operon, there are no features of the insertion sites to suggest target-specific insertion of IS1163. The overlapping, frameshifted organization of the two major open reading frames found in IS1163 is typical for the IS3 family, but the structure of the putative frameshift region includes features which distinguish IS1163 from the other members of the group. The insertional activity of IS1163 in L. sake L45 has aided in identifying regions of pCIM1 essential for lactocin S production and may have further practical applications as a mutational tool in L. sake.
authors.affiliation: Laboratory of Microbial Gene Technology, Agricultural University of Norway, As.
authors.forename: M
authors.initials: M
authors.lastname: Skaugen
authors.forename: I F
authors.initials: IF
authors.lastname: Nes
mesh_terms: D000595:Amino Acid Sequence; D001430:Bacteriocins / Q000096:biosynthesis* / Q000235:genetics; D001483:Base Sequence; D003001:Cloning, Molecular; D004251:DNA Transposable Elements / Q000235:genetics* / Q000502:physiology; D015964:Gene Expression Regulation, Bacterial / Q000235:genetics*; D005798:Genes, Bacterial / Q000235:genetics; D007778:Lactobacillus / Q000235:genetics* / Q000378:metabolism; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D016366:Open Reading Frames / Q000235:genetics; D012329:RNA, Bacterial / Q000737:chemistry; D012333:RNA, Messenger / Q000737:chemistry; D017422:Sequence Analysis, DNA
chemical_list: D001430:Bacteriocins; D004251:DNA Transposable Elements; D012329:RNA, Bacterial; D012333:RNA, Messenger; C035728:lactocin