Response regulators of bacterial signal transduction systems: selective domain shuffling during evolution

Area of Science:

• Microbiology
• Molecular Biology
• Bioinformatics

Background:

• Bacterial sensory transduction relies on response regulators, which integrate signals via receiver and effector domains.
• These domains control cellular responses, often through DNA binding or catalytic activity, modulated by phosphorylation.

Purpose of the Study:

• To investigate the evolutionary relationships between receiver modules and effector domains in bacterial response regulators.
• To classify response regulators based on the phylogenetic analysis of their constituent domains.

Main Methods:

• Phylogenetic analysis of receiver modules and effector domains from 49 response regulators.
• Comparison of phylogenetic trees to determine co-evolutionary patterns.
• Sequence alignment to identify conserved regions and residues.

Main Results:

• Three major clusters of receiver modules generally correspond to three major families of DNA-binding effector domains, forming three classes of response regulators.
• Minor receiver module clusters were often associated with other effector types.
• Evidence suggests co-evolution of receiver and effector domains, with some instances of domain shuffling.

Conclusions:

• Response regulator evolution is largely characterized by the co-divergence of receiver and effector domains.
• Domain shuffling played a role in the diversification of some response regulator families.
• Phylogenetic analysis provides a framework for understanding the structure-function relationships in these systems.