Landscape of mobile genetic elements and their antibiotic resistance cargo in prokaryotic genomes.

Prokaryotic Mobile Genetic Elements (MGEs) such as transposons, integrons, phages and plasmids, play important roles in prokaryotic evolution and in the dispersal of cargo functions like antibiotic resistance. However, each of these MGE types is usually annotated and analysed individually, hampering a global understanding of phylogenetic and environmental patterns of MGE dispersal. We thus developed a computational framework that captures diverse MGE types, their cargos and MGE-mediated horizontal transfer events, using recombinases as ubiquitous MGE marker genes and pangenome information for MGE boundary estimation.

Sequence analysis of tyrosine recombinases allows annotation of mobile genetic elements in prokaryotic genomes.

Mobile genetic elements (MGEs) sequester and mobilize antibiotic resistance genes across bacterial genomes. Efficient and reliable identification of such elements is necessary to follow resistance spreading. However, automated tools for MGE identification are missing.

Jump ahead with a twist: DNA acrobatics drive transposition forward.

Transposases move discrete pieces of DNA between genomic locations and had a profound impact on evolution. They drove the emergence of important biological functions and are the most frequent proteins encoded in modern genomes. Yet, the molecular principles of their actions have remained largely unclear.

Transposase-DNA Complex Structures Reveal Mechanisms for Conjugative Transposition of Antibiotic Resistance.

Conjugative transposition drives the emergence of multidrug resistance in diverse bacterial pathogens, yet the mechanisms are poorly characterized. The Tn1549 conjugative transposon propagates resistance to the antibiotic vancomycin used for severe drug-resistant infections. Here, we present four high-resolution structures of the conserved Y-transposase of Tn1549 complexed with circular transposon DNA intermediates.

Convergence of retrotransposons in oomycetes and plants.

Background: Retrotransposons comprise a ubiquitous and abundant class of eukaryotic transposable elements. All members of this class rely on reverse transcriptase activity to produce a DNA copy of the element from the RNA template. However, other activities of the retrotransposon-encoded polyprotein may differ between diverse retrotransposons.

Convergent evolution of ribonuclease h in LTR retrotransposons and retroviruses.

Ty3/Gypsy long terminals repeat (LTR) retrotransposons are structurally and phylogenetically close to retroviruses. Two notable structural differences between these groups of genetic elements are 1) the presence in retroviruses of an additional envelope gene, env, which mediates infection, and 2) a specific dual ribonuclease H (RNH) domain encoded by the retroviral pol gene. However, similar to retroviruses, many Ty3/Gypsy LTR retrotransposons harbor additional env-like genes, promoting concepts of the infective mode of these retrotransposons.

An integrated approach for genome annotation of the eukaryotic thermophile Chaetomium thermophilum.

The thermophilic fungus Chaetomium thermophilum holds great promise for structural biology. To increase the efficiency of its biochemical and structural characterization and to explore its thermophilic properties beyond those of individual proteins, we obtained transcriptomics and proteomics data, and integrated them with computational annotation methods and a multitude of biochemical experiments conducted by the structural biology community. We considerably improved the genome annotation of Chaetomium thermophilum and characterized the transcripts and expression of thousands of genes.

Acquisition of an Archaea-like ribonuclease H domain by plant L1 retrotransposons supports modular evolution.

Although a variety of non-LTR retrotransposons of the L1 superfamily have been found in plant genomes over recent decades, their diversity, distribution, and evolution have yet to be analyzed in depth. Here, we perform comprehensive comparative and evolutionary analyses of L1 retrotransposons from 29 genomes of land plants covering a wide range of taxa. We identify numerous L1 elements in these genomes and detect a striking diversity of their domain composition.