A NEW T4SS CLASSIFICATION BASED ON GENOMIC CONTEXT REVEALS VIRB2 PILIN HOMOLOGS IN MONODERM BACTERIA

Gianlucca Gonçalves Nicastro; Bruna Sayuri Cardoso Ogusku; Gabriel Sánchez Hueck; Cristiane Rodrigues Guzzo Carvalho; Robson Francisco de Souza

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Paper Title

A NEW T4SS CLASSIFICATION BASED ON GENOMIC CONTEXT REVEALS VIRB2 PILIN HOMOLOGS IN MONODERM BACTERIA

Authors

Gianlucca Gonçalves Nicastro
Bruna Sayuri Cardoso Ogusku
Gabriel Sánchez Hueck
Cristiane Rodrigues Guzzo Carvalho
Robson Francisco de Souza

Modality

Poster

Subject area

Phylogeny and Evolution

Publishing Date

08/11/2023

Country of Publishing

Brazil | Brasil

Language of Publishing

Inglês

Paper Page

https://www.even3.com.br/anais/xmeeting2023/637484-a-new-t4ss-classification-based-on-genomic-context-reveals-virb2-pilin-homologs-in-monoderm-bacteria

ISBN

978-65-272-0061-1

Keywords

Bioinformatics, T4SS, Secretion Systems, Phylogeny, VirB2

Summary

To interact with the environment and with other organisms, bacteria need to absorb and secrete different types of substrate, using secretion systems. The type IV secretion system (T4SS) stands out for its role in horizontal gene transfer (HGT), in which the genetic material is secreted by the system directly into another organism’s cells. HGT confers new characteristics that may favor the adaptation of the organism to environmental and competitive pressures. The T4SS also acts on the secretion of effector proteins crucial for pathogenesis, such as the secretion of the CagA protein of the Helicobacter pylori bacteria, responsible for lesions and ulcers in the human stomach. The classical T4SS vir system from Agrobacterium is composed of twelve proteins, VirB1 - VirB11 and VirD4, that form a structure that allows the transport of the substrate from the cytoplasm of the bacterium to the cytoplasm of infected plants. Two main classifications for T4SS are in use, the first being based on the biological process that the whole system takes part, such as conjugation and DNA transfer or effector secretion. The second classification system, introduced by Guglielmini and collaborators, is based on the phylogeny of the two most conserved ATPases, VirB4 and VirD4, and introduces eight subtypes that are highly correlated with the organisms taxonomy. While searching for new T4SS systems and associated proteins, we built HMM models from alignments of each component of all different subtypes, as well as more generic models, aiming to achieve greater sensitivity, and used this models in searches against the public protein databases. The collected homologs were used to identify conserved gene neighborhoods extending up to 10 upstream and 10 downstream genes. Detailed analysis of protein sequences and structures of the proteins encoded in these conserved gene neighborhoods, coupled with careful phylogenetic analysis of the ATPases, revealed four new phylogenetic subgroups (ACT, ACC, FI and CPR) and the widespread presence of hitherto unrecognized homologs of the VirB2 protein, the main pilin of the system, in monodermal bacteria. The demonstration that such pilins are found in monodermal lineages provides new insights and venues for experimental research in the overlooked realm of T4SS systems present in these bacterial lineages.

Title of the Event: X-Meeting / BSB 2023
City of the Event: Curitiba
Title of the Proceedings of the event: X-Meeting presentations
Name of the Publisher: Even3
Means of Dissemination: Meio Digital

How to cite

NICASTRO, Gianlucca Gonçalves et al.. A NEW T4SS CLASSIFICATION BASED ON GENOMIC CONTEXT REVEALS VIRB2 PILIN HOMOLOGS IN MONODERM BACTERIA.. In: X-Meeting presentations. Anais...Curitiba(PR) Campus da indústria, 2023. Available in: https//www.even3.com.br/anais/xmeeting2023/637484-A-NEW-T4SS-CLASSIFICATION-BASED-ON-GENOMIC-CONTEXT-REVEALS-VIRB2-PILIN-HOMOLOGS-IN-MONODERM-BACTERIA. Access in: 16/07/2025