title: Structures of the arm-type binding domains of HPI and HAI7 integrases.
abstract: The structures of the N-terminal domains of two integrases of closely related but not identical asn tDNA-associated genomic islands, Yersinia HPI (high pathogenicity island; encoding siderophore yersiniabactin biosynthesis and transport) and an Erwinia carotovora genomic island with yet unknown function, HAI7, have been resolved. Both integrases utilize a novel four-stranded beta-sheet DNA-binding motif, in contrast to the known proteins that bind their DNA targets by means of three-stranded beta-sheets. Moreover, the beta-sheets in Int(HPI) and Int(HAI7) are longer than those in other integrases, and the structured helical N terminus is positioned perpendicularly to the large C-terminal helix. These differences strongly support the proposal that the integrases of the genomic islands make up a distinct evolutionary branch of the site-specific recombinases that utilize a unique DNA-binding mechanism.
authors.affiliation: Max Planck Institute for Biochemistry, D-82152 Martinsried, Germany.
authors.forename: Aleksandra
authors.initials: A
authors.lastname: Szwagierczak
authors.forename: Uladzimir
authors.initials: U
authors.lastname: Antonenka
authors.forename: Grzegorz M
authors.initials: GM
authors.lastname: Popowicz
authors.forename: Tomasz
authors.initials: T
authors.lastname: Sitar
authors.forename: Tad A
authors.initials: TA
authors.lastname: Holak
authors.forename: Alexander
authors.initials: A
authors.lastname: Rakin
mesh_terms: D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry; D003066:Coenzyme A Ligases / Q000737:chemistry; D003460:Crystallization; D004269:DNA, Bacterial / Q000235:genetics / Q000378:metabolism; D024202:Electrophoretic Mobility Shift Assay; D044404:Genomic Islands; D019426:Integrases / Q000737:chemistry* / Q000235:genetics; D008969:Molecular Sequence Data; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D017386:Sequence Homology, Amino Acid; D015010:Yersinia pestis / Q000201:enzymology*
chemical_list: D001426:Bacterial Proteins; D004269:DNA, Bacterial; D019426:Integrases; D003066:Coenzyme A Ligases; C408477:YbtE protein, Yersinia pestis