Comparative Study of the Twin Arginine Translocase (Tat) System Across Bacterial Species: Insights into Hydrophobic Interactions, Signal Peptide Binding and Protein Translocation Dynamics

This study examines the Twin-Arginine Translocase (Tat) system, especially the TatC subunit's role and variations between Gram-positive and Gram-negative bacteria. It investigates how hydrophobicity affects the Tat pathway, particularly in the interaction of the Escherichia coli (E. coli) TatC subunit and Bacillus substilis (B. subtilis) with SufI and TorA signal peptides. Different bioinformatics tools were used in the following research such as NCBI, Clustal Omega, MAFFT for sequence alignment, Phyre2 for structural modelling, and PyMOL, HDOCK, POCASA, KVFinder for protein docking and hydrophobicity analysis. The study provides an in-depth examination of TatC's structure, evolutionary relationships, and interactions with signal peptides. This approach uncovers the crucial balance between hydrophobic and hydrophilic forces in the Tat pathway, challenging the traditional emphasis on the twin-arginine motif in the SufI and TorA signal peptide. The analysis reveals the binding affinities and the pivotal role of the regions of the signal peptide interactions within TatC subunit in particular from Gram-negative E. coli and Gram-positive B. subtilis, enriching comprehension of the system's flexibility and the fundamental influence of hydrophobicity in protein interactions. The current study also demonstrates that peptides can bind effectively without twin-arginine motifs and suggests a deeper embedding of signal peptides in TatC's hydrophobic zones.