A LARGE-SCALE SURVEY OF BACTERIAL AND ARCHAEAL GENOMES REVEALS NOVEL FAMILIES OF CASPOSON ELEMENTS

Julia Stutz Fiasca; Liliane Santana; Desconhecido766

All Papers

Submission

Paper Title

A LARGE-SCALE SURVEY OF BACTERIAL AND ARCHAEAL GENOMES REVEALS NOVEL FAMILIES OF CASPOSON ELEMENTS

Authors

Julia Stutz Fiasca
Liliane Santana
Desconhecido766

Modality

Xpress presentation

Subject area

Omics

Publishing Date

26/04/2022

Country of Publishing

Brasil

Language of Publishing

Inglês

Paper Page

https://www.even3.com.br/anais/xmeetingxp2021/419686-a-large-scale-survey-of-bacterial-and-archaeal-genomes-reveals-novel-families-of-casposon-elements

ISBN

978-65-5941-645-5

Keywords

Casposon,profile HMM,prokaryotyc genomes,transposable elements

Summary

Casposons is a group of self-synthesizing DNA transposable elements found in bacterial and archaeal genomes. These elements comprise several genes, including two that are ubiquitous, cas1 and polb. Cas1 gene codes for endonuclease Cas1, a key enzyme of the adaptive immunity of CRISPR-Cas system, whereas polb encodes a type B DNA polymerase. The remaining genes are not shared by all elements. A total of four distinct families have been described for casposons. Family 1 is composed of elements of archaeal hosts, presenting a protein-primed PolB, an enzyme closely related to polymerases of archaeal viruses. Elements of the other families were found in Archaea (Families 2 and 4) and Bacteria (Family 3). The importance of casposon elements relies on the hypothesis that they may have originated CRISPR-Cas systems. A few casposons were found in Streptomyces hosts, associated to genes encoding a double-jelly roll major capsid protein (DJR-MCP) and a DNA-packaging ATPase, which typically belong to Toil-like prophages of the Tectiviridae family. To understand the evolutive role of casposons in the emergence of adaptive immunity in prokaryotes and their possible association with Tectiviridae viruses, we performed a large-scale survey on PATRIC, a public repository of assembled genomes. We used TABAJARA program to construct sets of casposon-specific profile HMMs, derived from Cas1 and PolB sequences. We also built models using DJP-MCP and ATPase sequences originated from tectiviruses. These sets of profile HMMs were used with e-Finder, a generic tool for the detection of multigene elements. In total, we identified more than 200 typical casposons. From this group, eight elements showed association with Tectiviridae prophages, all of them hosted in different species of the genus Streptomyces. A phylogenetic analysis confirmed the monophyletic character of casposons in regard to CRISPRs. Two new groups of elements, composing clades that are distinct from families 1 to 4, were also found. These new casposon groups were detected in Actinobacteria and Acidobacteria phyla, respectively. The former group also contains the elements associated to tectiviruses and hosted in Streptomyces. This body of evidence suggests that, in addition to the four original casposon families, at least two novel families, found in previously undescribed bacterial hosts, can be included in the casposon superfamily. We intend to extend this characterization to better understand the possible evolutionary pathways of casposon elements.

Title of the Event: X-Meeting XPerience 2021
Title of the Proceedings of the event: X-Meeting presentations
Name of the Publisher: Even3
Means of Dissemination: Meio Digital

How to cite

FIASCA, Julia Stutz; SANTANA, Liliane; , Desconhecido766. A LARGE-SCALE SURVEY OF BACTERIAL AND ARCHAEAL GENOMES REVEALS NOVEL FAMILIES OF CASPOSON ELEMENTS.. In: X-Meeting presentations. Anais...São Paulo(SP) AB3C, 2021. Available in: https//www.even3.com.br/anais/xmeetingxp2021/419686-A-LARGE-SCALE-SURVEY-OF-BACTERIAL-AND-ARCHAEAL-GENOMES-REVEALS-NOVEL-FAMILIES-OF-CASPOSON-ELEMENTS. Access in: 21/05/2025