Bioinformatic analysis of the flagellar system of the rickettsia-like alphaproteobacteria Candidatus Hepatobacter penaei

Abstract

The presence of flagellar systems is common in several free-living bacteria; however, these have been considered absent in bacteria belonging to the Rickettsiales order. Candidatus Hepatobacter penaei is a marine Rickettsial bacterium described as a motile microorganism propelled by a flagellar system that facilitates infection. This bacterium represents a major risk of infection in shrimp farms. Therefore, the objective of this study was to determine the presence of genes encoding the flagellar system proteins of the bacterium Candidatus Hepatobacter penaei. The genomic sequence of the GenBank database with accession number NZ_JQAJ00000000.1, was analyzed. After genes were identified, amino acid sequences were deduced. The amino acid sequences of the flagellar system were identified by BLASTP through multiple alignment of conserved domains. Subsequently, a modeling process of FlhA protein was performed and compared with the protein reported for Oceanibaculum indicum considering the formation of -helixes and -sheets. Results showed the presence of some amino acid sequences of the genes related to bacterial flagellar system as MotA FliG, FliN, FliL FlhA, FlhB, FliQ FliR and FliF. Finally, these results suggest that Candidatus Hepatobacter penaei is a rickettsial bacterium having a flagellar system, which possibly confers motility and take part in the infection process in hosts such as marine crustaceans.