AUTHOR=Merino Susana , Tomás Juan M. 

TITLE=The FlgT Protein Is Involved in Aeromonas hydrophila Polar Flagella Stability and Not Affects Anchorage of Lateral Flagella

JOURNAL=Frontiers in Microbiology

VOLUME=7

YEAR=2016

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2016.01150

DOI=10.3389/fmicb.2016.01150

ISSN=1664-302X

ABSTRACT=<p><italic>Aeromonas hydrophila</italic> sodium-driven polar flagellum has a complex stator-motor. Consist of two sets of redundant and non-exchangeable proteins (PomA/PomB and PomA<sub>2</sub>/PomB<sub>2</sub>), which are homologs to other sodium-conducting polar flagellum stator motors; and also two essential proteins (MotX and MotY), that they interact with one of those two redundant pairs of proteins and form the T-ring. In this work, we described an essential protein for polar flagellum stability and rotation which is orthologs to <italic>Vibrio</italic> spp. FlgT and it is encoded outside of the <italic>A. hydrophila</italic> polar flagellum regions. The <italic>flgT</italic> was present in all mesophilic <italic>Aeromonas</italic> strains tested and also in the non-motile <italic>Aeromonas salmonicida</italic>. The <italic>A. hydrophila</italic> Δ<italic>flgT</italic> mutant is able to assemble the polar flagellum but is more unstable and released into the culture supernatant from the cell upon completion assembly. Presence of FlgT in purified polar hook-basal bodies (HBB) of wild-type strain was confirmed by Western blotting and electron microscopy observations showed an outer ring of the T-ring (H-ring) which is not present in the Δ<italic>flgT</italic> mutant. Anchoring and motility of proton-driven lateral flagella was not affected in the Δ<italic>flgT</italic> mutant and specific antibodies did not detect FlgT in purified lateral HBB of wild type strain.</p>