Detailed analysis of the insertion site of the mobile elements R997, pMERPH, R392, R705 and R391 inE. coliK12

Abstract

The IncJ group of mobile elements have not been extensively studied until recently, due to the inability to isolate extrachromosomal DNA from IncJ-strains. Sequence analysis of the prototype IncJ element, R391, revealed it to be a mosaic structure, integrated into the prfC gene in E. coli. Using inverse PCR (iPCR), we localised the other available IncJ elements (R392, R705, R997 and pMERPH) site of insertion to a 17-bp sequence, within the 5' end of prfC at 99.31 min on the E. coli chromosome, and confirmed this for R391. Despite disrupting prfC, the IncJ's encode novel promoter and 5' sequences, restoring function of the disrupted prfC. Sequence analysis of the elements ends revealed that they contain integrase genes, which share extensive homologies among the group, despite being isolated from broad geographic locations. The elements excise from the host chromosome by recombination between their attL and attR sites, with subsequent recombination between the attP sites on the circular forms and the attB sites in the host genomes. The attB site is highly conserved and found in many different bacteria, suggesting a possible broad host range.

Genetic Characterization of Four Groups of Chromosome-Borne Accessory Genetic Elements Carrying Drug Resistance Genes in Providencia

“…Conjugal transfer experiments confirm that Tn 6512 -related ICEs with the complete gene sets for conjugal transfer have the ability to transfer from the wild-type isolates of Proteus , 40 Vibrio , 41 Shewanella , 42 and Providencia (this study) to the recipient bacteria E. coli , and that a circular extrachromosomal Tn 6512 has the ability to transfer into the recipient bacteria Salmonella , 39 Enterobacter , 39 and Serratia , 39 indicating that this group of ICEs have a very broad host range.…”

“…Integration of these ICEs needs the 17-bp relatively non-conserved attB (attachment site on the chromosome) target sites within the 5’ end of prfC , 32 and can occur with up to 23.5% sequence mismatch between attB and attP . 39 These attB sites together with Tn 6512 -related ICEs are widely distributed in Gram-negative bacteria as mentioned above. Taken together, Tn 7 -related unit transposons and Tn 6512 -related ICEs have a wide host range.…”

Deciphering the Structural Diversity and Classification of the Mobile Tigecycline Resistance Gene tet (X)-Bearing Plasmidome among Bacteria

“…Coincidentally, R391 was also first discovered in a Providencia rettgeri clinical isolate (52) and was later classified as the SXT/R391 family (53)(54)(55). The ICE in strain RF14-2 integrated into the 5= end of the gene prfC, which was a typical characteristic of all members of the SXT/R391 family (55,56). This novel SXT/R391 ICE was designated ICEPreChnRF14-2 according to the nomenclature system (54).…”

A Novel Arsenate-Resistant Determinant Associated with ICEpMERPH, a Member of the SXT/R391 Group of Mobile Genetic Elements

“…Type 1 elements have been found in a variety of Gammaproteobacteria species, including the Vibrio, Shewanella, Proteus, and Photobacterium (a full list can be found in Supplementary Table S1 ). They are distinguished by possessing a type 1 integrase, which allows for site-specific integration into the 5 end of the essential prfC gene [54]. Integration restores a functioning prf C gene and encodes a new hybrid PrfC protein [54].…”

“…They are distinguished by possessing a type 1 integrase, which allows for site-specific integration into the 5 end of the essential prfC gene [54]. Integration restores a functioning prf C gene and encodes a new hybrid PrfC protein [54]. Type 2,3,and 4 ICEs all insert at the 3 end of the multicopy tRNA-Ser gene and have been found solely in Vibrio species [3,55].…”