Project description:Retrons are bacterial genetic elements that encode a reverse transcriptase and, in combination with toxic effector proteins, can serve as antiphage defense systems. However, the mechanisms of action of most retron effectors, and how phages evade retrons, are not well understood. Here, we show that some phages can evade retrons and other defense systems by producing specific tRNAs. We find that expression of retron-Eco7 effector proteins (PtuA and PtuB) leads to degradation of tRNA-Tyr and abortive infection. The genomes of T5 phages that evade retron-Eco7 include a tRNA-rich region, including a highly expressed tRNA-Tyr gene, which confers protection against retron-Eco7. Furthermore, we show that other phages (T1, T7) can use a similar strategy, expressing a tRNA-Lys, to counteract a tRNA anticodon defense system (PrrC170).

2024-09-12 | GSE229290 | GEO

Acinetobacter baumannii

Project description:Acinetobacter phages Genome sequencing and assembly

| PRJNA608808 | ENA

Phage-encoded sigma factors alter bacterial dormancy

Project description:By entering a reversible state of reduced metabolic activity, dormant microorganisms are able to contend with suboptimal conditions that would otherwise reduce their fitness. In addition, certain types of dormancy like sporulation, can serve as a refuge from parasitic infections. Phages are unable to attach to spores, but their genomes can be entrapped in the resting structures and are able to resume infection upon host germination. Thus, dormancy has the potential to affect both the reproductive and survival components of phage fitness. Here, we characterized the distribution and diversity of sigma factors in nearly 3,500 phage genomes. Homologs of bacterial sigma factors that are responsible for directing transcription during sporulation were preferentially recovered in phages that infect spore-forming hosts. While non-essential for lytic infection, when expressed in Bacillus subtilis, we demonstrate that phage-encoded sigma factors activated sporulation gene networks and reduced spore yield. Our findings suggest that the acquisition of host-like transcriptional regulators may allow phages to manipulate the expression of complex traits, like the transitions involved in bacterial dormancy.

2021-11-05 | GSE187004 | GEO

Acinetobacter phage Acba_3

Project description:Acinetobacter phage Acba_3, genome sequencing and assembly

| PRJNA912606 | ENA

Acinetobacter phage vB_AbM_ABWU1901

Project description:Acinetobacter phage vB_AbM_ABWU1901 Genome sequencing and assembly

| PRJNA753305 | ENA

Acinetobacter phage Ab_WF01

Project description:Acinetobacter phage Ab_WF01 Genome sequencing and assembly

| PRJNA946663 | ENA

Acinetobacter phage EAb13

Project description:Acinetobacter phage EAb13 Genome sequencing and assembly