Structures of the arm-type binding domains of HPI and HAI7 integrases.
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.
Szwagierczak
Aleksandra
A
Max Planck Institute for Biochemistry, D-82152 Martinsried, Germany.
Antonenka
Uladzimir
U
Popowicz
Grzegorz M
GM
Sitar
Tomasz
T
Holak
Tad A
TA
Rakin
Alexander
A
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*
D001426:Bacterial Proteins; D004269:DNA, Bacterial; D019426:Integrases; D003066:Coenzyme A Ligases; C408477:YbtE protein, Yersinia pestis