Skip to main content
ARS Home » Research » Publications at this Location » Publication #60001
Title: CHARACTERIZATION OF IS1500, AN ELEMENT WHICH RESEMBLES IS3 OF ESCHERICHIA COLI, FROM LEPTOSPIRA INTERROGANS

Author
item BOURSAUX-EUDE, C - INSTITUT PASTUER, FRANCE
item Zuerner, Richard
item SAINT GIRONS, I - INSTITUT PASTUER, FRANCE

Submitted to: French Society for Microbiology Annual Meeting
Publication Type: Abstract Only
Publication Acceptance Date: 5/5/1995
Publication Date: N/A
Citation: N/A

Interpretive Summary:

Technical Abstract: The diversity among leptospires seems to raise the importance of rearrangements at the genomic level. In order to better understand these events, we have isolated and cloned a novel insertion sequence, IS1500, from two strains of Leptospira interrogans, IS1500A from serovar icterohaemorrhagiae strain Verdun, and IS1500B from serovar pomona strain RZ11. These elements were also found in the other species of pathogenic Leptospira. No IS were identified in the serovars of saprophytic leptospires. IS1500A and B have a size of 1236 bp and are 98% identical at the level of their nucleic acid sequence. The potential proteins coded by the ORFA and B possess some homology with two ORFs of IS3 of E. Coli. The product of ORFB shares 35% identity with the transposase of IS3 and ORFA specifies a regulator capable of repressing the activity of the transposase necessary for defining an IS. We have found a Leucine zipper motif in the protein potentially encoded by ORFA. Like E. Coli, there is some shift of reading frame identified between ORFA and B. The functional transposase would result by the fusion of the products of the two ORFs. A Helix-Turn-H of IS1500 possesses some imperfect Inverted Repeat Sequences 38 bp (on the left) and 39 bp (on the right) identical in the two strains studied. The elements have been mapped on the 4610 kbp circular chromosome of the two strains studied. These two strains present very different genetic maps and have some sites of rearrangements. The comparison of the distribution of IS1500 allowed some of the insertion sequences to be mapped near these rearrangements. This, therefore, favors a role of these elements in the heterogeneity of the organization of the Leptospira genome.