IS1626, a new IS900-related Mycobacterium avium insertion sequence

Area of Science:

• Microbiology
• Genetics
• Molecular Biology

Background:

• Insertion sequences (IS) are mobile genetic elements that play roles in genome evolution.
• IS elements are found in various bacteria, including clinically relevant species like Mycobacterium avium.
• Understanding IS elements aids in studying bacterial adaptation and evolution.

Purpose of the Study:

• To isolate and characterize a novel insertion sequence, IS1626, from a clinical Mycobacterium avium strain.
• To determine the molecular features and insertion mechanism of IS1626.
• To compare IS1626 with related IS elements to understand their evolutionary significance.

Main Methods:

• High-stringency hybridization using a probe from IS900 of Mycobacterium paratuberculosis.
• DNA sequencing to determine the size, G+C content, and open reading frames (ORFs) of IS1626.
• Analysis of insertion sites in M. avium strains to identify consensus target sequences.

Main Results:

• IS1626 is a 1418 bp insertion sequence with a G+C content of 65 mol%.
• It lacks terminal inverted and flanking direct repeats.
• A consensus insertion sequence of CATGCN(4-5)TCCTN(2)G was identified, with IS1626 showing consistent orientation at insertion sites.
• Two major ORFs were identified, encoding predicted proteins of 393 and 310 amino acids, with ORF930 exhibiting features similar to IS900-related elements.

Conclusions:

• IS1626 is a novel insertion sequence in Mycobacterium avium, related to IS900 elements.
• Its characterization provides a target sequence for insertion, contributing to the understanding of mobile genetic elements.
• The study highlights the utility of analyzing IS elements for insights into bacterial evolution and host-pathogen interactions.