Mycobacteriophage Bxb1 integrates into the Mycobacterium smegmatis groEL1 gene.
Mycobacteriophage Bxb1 is a temperate phage of Mycobacterium smegmatis and forms stable lysogens in which the Bxb1 genome is integrated into the host chromosome. Bxb1 encodes an integrase of the large serine recombinase family that catalyses integration and excision of the Bxb1 genome. We show here that Bxb1 integrates into a chromosomal attB site located within the 3' end of the groEL1 gene such that integration results in alteration of the C-terminal 21 amino acid residues. An integration-proficient plasmid vector containing the Bxb1 integrase gene and flanking DNA sequences efficiently transforms M. smegmatis via integration at attB. Bxb1-integrated recombinants are stable and fully compatible with L5 integration vectors. Strand exchange occurs within an 8 bp common core sequence present in attB and within an attP site situated immediately upstream of the phage integrase gene. Establishment of a defined in vitro system for Bxb1 integration shows that recombination occurs efficiently without requirement for high-energy cofactors, divalent metals, DNA supercoiling or additional proteins.
Kim
Amy I
AI
Department of Biological Sciences and Pittsburgh Bacteriophage Institute, University of Pittsburgh, Pittsburgh, PA 15260, USA.
Ghosh
Pallavi
P
Aaron
Michelle A
MA
Bibb
Lori A
LA
Jain
Shruti
S
Hatfull
Graham F
GF
D000595:Amino Acid Sequence; D018834:Chaperonin 60 / Q000235:genetics*; D004269:DNA, Bacterial / Q000235:genetics; D004279:DNA, Viral / Q000235:genetics; D005814:Genes, Viral; D005822:Genetic Vectors; D008242:Lysogeny; D008969:Molecular Sequence Data; D009160:Mycobacteriophages / Q000235:genetics*; D009161:Mycobacterium / Q000235:genetics*; D010957:Plasmids; D012097:Repressor Proteins / Q000235:genetics*; D014764:Viral Proteins / Q000235:genetics*; D016662:Virus Integration
D018834:Chaperonin 60; D004269:DNA, Bacterial; D004279:DNA, Viral; D012097:Repressor Proteins; D014764:Viral Proteins; C419551:gp69 protein, Mycobacteriophage Bxb1