<b>Distributional and evolutionary analyses of the </b><b><i>Escherichia coli</i></b><b> deubiquitinase ElaD through integrated bioinformatics analysis</b>

Pathogens employ a variety of effector proteins to modulate key host signaling pathways, thereby facilitating bacterial survival and enhancing pathogenicity. Despite lacking a complete ubiquitin system of their own, bacterial effector proteins frequently function as ubiquitin ligases or deubiquitinases (DUBs) to disrupt the eukaryotic ubiquitin machinery. DUBs have been found in a variety of bacteria, including ElaD, which has recently been recognized as a DUB in <i>Escherichia coli</i> (<i>E. coli</i>). However, the distributional and evolutionary analyses of ElaD in different <i>E. coli</i> remains largely unknown. In this study, we retrieved and analyzed the <i>elaD</i> gene sequences from the genomes of 530 <i>E. coli</i> strains. Then, molecular characterization of each strain was determined by bioinformatics methods. Phylogenetic tree was also constructed to analyze the evolutionary relationships between different ElaDs. Our findings demonstrate that the <i>elaD</i> gene was present in 66.60% (353/530) of both pathogenic and nonpathogenic <i>E. coli</i> strains. <i>elaD</i> gene is predominantly found in the O157, O26, O139 and O8 serotypes. The majority of <i>elaD</i>-positive strains belonged to phylogenetic groups B1, A, E and D, with the predominant sequence types being ST11, ST21, ST10, ST1 and ST69. ElaDs from different strains clustered in the phylogenetic tree in a correlation with O serotypes and phylogenetic groups. In addition, ElaDs of some branches showed premature translation termination. The widespread occurrence of the <i>elaD</i> gene among various <i>E. coli</i> strains suggests its potential significance in <i>E. coli</i> pathogenicity, although its precise functional role remains to be elucidated.