Sequential induction of three recombination directionality factors directs assembly of tripartite integrative and conjugative elements

Autor: Jason Terpolilli, Phillip S. Poole, Callum J. Verdonk, Joshua P. Ramsay, Graham O’Hara, Vinoy K. Ramachandran, Timothy L. Haskett
Jazyk: angličtina
Rok vydání: 2018
Předmět:
0301 basic medicine
Cancer Research
Biochemistry
Database and Informatics Methods
Recombinase
Genetics (clinical)
Recombination
Genetic
Chemical Reactions
High-Throughput Nucleotide Sequencing
Quorum Sensing
Recombination Reactions
Chromosomes
Bacterial
Recombinant Proteins
RNA
Bacterial
Chemistry
DNA Nucleotidyltransferases
Physical Sciences
Horizontal gene transfer
Sequence Analysis
Recombination
Research Article
Multiple Alignment Calculation
Gene Transfer
Horizontal
lcsh:QH426-470
Bioinformatics
DNA transcription
030106 microbiology
Sequence alignment
Computational biology
DNA construction
Biology
Real-Time Polymerase Chain Reaction
Research and Analysis Methods
Viral Proteins
03 medical and health sciences
Computational Techniques
Genetics
Directionality
Amino Acid Sequence
Molecular Biology
Ecology
Evolution
Behavior and Systematics
Mesorhizobium
Gene Amplification
Biology and Life Sciences
Proteins
Split-Decomposition Method
Quorum sensing
lcsh:Genetics
Molecular biology techniques
030104 developmental biology
Genes
Bacterial
Plasmid Construction
Excisionase
Gene expression
Mobile genetic elements
Sequence Alignment
Zdroj: PLoS Genetics, Vol 14, Iss 3, p e1007292 (2018)
PLoS Genetics
ISSN: 1553-7404
1553-7390
Popis: Tripartite integrative and conjugative elements (ICE3) are a novel form of ICE that exist as three separate DNA regions integrated within the genomes of Mesorhizobium spp. Prior to conjugative transfer the three ICE3 regions of M. ciceri WSM1271 ICEMcSym1271 combine and excise to form a single circular element. This assembly requires three coordinated recombination events involving three site-specific recombinases IntS, IntG and IntM. Here, we demonstrate that three excisionases–or recombination directionality factors—RdfS, RdfG and RdfM are required for ICE3 excision. Transcriptome sequencing revealed that expression of ICE3 transfer and conjugation genes was induced by quorum sensing. Quorum sensing activated expression of rdfS, and in turn RdfS stimulated transcription of both rdfG and rdfM. Therefore, RdfS acts as a “master controller” of ICE3 assembly and excision. The dependence of all three excisive reactions on RdfS ensures that ICE3 excision occurs via a stepwise sequence of recombination events that avoids splitting the chromosome into a non-viable configuration. These discoveries expose a surprisingly simple control system guiding molecular assembly of these novel and complex mobile genetic elements and highlight the diverse and critical functions of excisionase proteins in control of horizontal gene transfer.
Author summary Bacteria evolve and adapt quickly through the horizontal transfer of DNA. A major mechanism facilitating this transfer is conjugation. Conjugative DNA elements that integrate into the chromosome are termed ‘Integrative and Conjugative Elements’ (ICE). We recently discovered a unique form of ICE that undergoes a complex series of recombination events with the host chromosome to split itself into three separate parts. This tripartite ICE must also precisely order its recombination when leaving the current host to avoid splitting the host chromosome and the ICE into non-viable parts. In this work, we show that the tripartite ICEs use chemical cell-cell communication to stimulate recombination and that recombination events are specifically ordered through cascaded transcriptional activation of small DNA-binding proteins called recombination directionality factors. Despite the inherent complexity of tripartite ICEs this work exposes a surprisingly simple system to stimulate their precise and ordered molecular assembly prior to horizontal transfer.
Databáze: OpenAIRE
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