title: Structural organization of a complex family of palindromic repeats in Enterococci.
abstract: Enterococcus faecalis/faecium repeats (EFARs) are miniature insertion sequences spread in the genome of Enterococcus faecalis and Enterococcus faecium. Unit-length repeats measure 165-170 bp and contain two modules (B and T) capable of folding independently into stem-loop sequences, connected by a short, unstructured module J. The E. faecalis elements feature only one type of B, J and T modules. In contrast, the E. faecium elements result from the assembly of different types of B, J and T modules, and may vary in length because they carry multiple B modules. Most EFARs are located close (0-20 bp) to ORF stop codons, and are thus cotranscribed with upstream flanking genes. In both E. faecalis and E. faecium cells, EFAR transcripts accumulate in a strand-dependent fashion. Data suggest that T modules function as bidirectional transcriptional terminators, which provide a 3'-end to gene transcripts spanning B modules, while blocking antisense transcripts coming in from the opposite direction.
authors.affiliation: Dipartimento di Biologia e Patologia Cellulare e Molecolare, Università Federico II, Napoli, Italy.
authors.forename: Eliana
authors.initials: E
authors.lastname: De Gregorio
authors.forename: Tullia
authors.initials: T
authors.lastname: Bertocco
authors.forename: Giustina
authors.initials: G
authors.lastname: Silvestro
authors.forename: M Stella
authors.initials: MS
authors.lastname: Carlomagno
authors.forename: Raffaele
authors.initials: R
authors.lastname: Zarrilli
authors.forename: Pier Paolo
authors.initials: PP
authors.lastname: Di Nocera
mesh_terms: D001483:Base Sequence; D004269:DNA, Bacterial / Q000235:genetics*; D013293:Enterococcus faecalis / Q000235:genetics*; D016984:Enterococcus faecium / Q000235:genetics*; D055029:Inverted Repeat Sequences; D008969:Molecular Sequence Data; D016415:Sequence Alignment
chemical_list: D004269:DNA, Bacterial