{"title":"IS<i>26</i> and the IS<i>26</i> family: versatile resistance gene movers and genome reorganizers.","authors":"Christopher J Harmer, Ruth M Hall","doi":"10.1128/mmbr.00119-22","DOIUrl":null,"url":null,"abstract":"<p><p><b>SUMMARY</b>In Gram-negative bacteria, the insertion sequence IS<i>26</i> is highly active in disseminating antibiotic resistance genes. IS<i>26</i> can recruit a gene or group of genes into the mobile gene pool and support their continued dissemination to new locations by creating pseudo-compound transposons (PCTs) that can be further mobilized by the insertion sequence (IS). IS<i>26</i> can also enhance expression of adjacent potential resistance genes. IS<i>26</i> encodes a DDE transposase but has unique properties. It forms cointegrates between two separate DNA molecules using two mechanisms. The well-known copy-in (replicative) route generates an additional IS copy and duplicates the target site. The recently discovered and more efficient and targeted conservative mechanism requires an IS in both participating molecules and does not generate any new sequence. The unit of movement for PCTs, known as a translocatable unit or TU, includes only one IS<i>26</i>. TU formed by homologous recombination between the bounding IS<i>26</i>s can be reincorporated via either cointegration route. However, the targeted conservative reaction is key to generation of arrays of overlapping PCTs seen in resistant pathogens. Using the copy-in route, IS<i>26</i> can also act on a site in the same DNA molecule, either inverting adjacent DNA or generating an adjacent deletion plus a circular molecule carrying the DNA segment lost and an IS copy. If reincorporated, these circular molecules create a new PCT. IS<i>26</i> is the best characterized IS in the IS<i>26</i> family, which includes IS<i>257</i>/IS<i>431</i>, ISSau10, IS<i>1216</i>, IS<i>1006</i>, and IS<i>1008</i> that are also implicated in spreading resistance genes in Gram-positive and Gram-negative pathogens.</p>","PeriodicalId":18520,"journal":{"name":"Microbiology and Molecular Biology Reviews","volume":null,"pages":null},"PeriodicalIF":8.0000,"publicationDate":"2024-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11332343/pdf/","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Microbiology and Molecular Biology Reviews","FirstCategoryId":"99","ListUrlMain":"https://doi.org/10.1128/mmbr.00119-22","RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"2024/3/4 0:00:00","PubModel":"Epub","JCR":"Q1","JCRName":"MICROBIOLOGY","Score":null,"Total":0}
引用次数: 0
Abstract
SUMMARYIn Gram-negative bacteria, the insertion sequence IS26 is highly active in disseminating antibiotic resistance genes. IS26 can recruit a gene or group of genes into the mobile gene pool and support their continued dissemination to new locations by creating pseudo-compound transposons (PCTs) that can be further mobilized by the insertion sequence (IS). IS26 can also enhance expression of adjacent potential resistance genes. IS26 encodes a DDE transposase but has unique properties. It forms cointegrates between two separate DNA molecules using two mechanisms. The well-known copy-in (replicative) route generates an additional IS copy and duplicates the target site. The recently discovered and more efficient and targeted conservative mechanism requires an IS in both participating molecules and does not generate any new sequence. The unit of movement for PCTs, known as a translocatable unit or TU, includes only one IS26. TU formed by homologous recombination between the bounding IS26s can be reincorporated via either cointegration route. However, the targeted conservative reaction is key to generation of arrays of overlapping PCTs seen in resistant pathogens. Using the copy-in route, IS26 can also act on a site in the same DNA molecule, either inverting adjacent DNA or generating an adjacent deletion plus a circular molecule carrying the DNA segment lost and an IS copy. If reincorporated, these circular molecules create a new PCT. IS26 is the best characterized IS in the IS26 family, which includes IS257/IS431, ISSau10, IS1216, IS1006, and IS1008 that are also implicated in spreading resistance genes in Gram-positive and Gram-negative pathogens.
期刊介绍:
Microbiology and Molecular Biology Reviews (MMBR), a journal that explores the significance and interrelationships of recent discoveries in various microbiology fields, publishes review articles that help both specialists and nonspecialists understand and apply the latest findings in their own research. MMBR covers a wide range of topics in microbiology, including microbial ecology, evolution, parasitology, biotechnology, and immunology. The journal caters to scientists with diverse interests in all areas of microbial science and encompasses viruses, bacteria, archaea, fungi, unicellular eukaryotes, and microbial parasites. MMBR primarily publishes authoritative and critical reviews that push the boundaries of knowledge, appealing to both specialists and generalists. The journal often includes descriptive figures and tables to enhance understanding. Indexed/Abstracted in various databases such as Agricola, BIOSIS Previews, CAB Abstracts, Cambridge Scientific Abstracts, Chemical Abstracts Service, Current Contents- Life Sciences, EMBASE, Food Science and Technology Abstracts, Illustrata, MEDLINE, Science Citation Index Expanded (Web of Science), Summon, and Scopus, among others.