Questioning rotary functionality in the bacterial flagellar system and proposing a murburn model for motility
Creators: name: Manoj, Kelath Murali
name: Jacob, Vivian David
name: Kavdia, Mahendra
name: Tamagawa, Hirohisa
name: Jaeken, Laurent
name: Soman, Vidhu
Publisher: name: Taylor & Francis
Year: 2023
Subjects: subject: Biophysics
subject: Biochemistry
subject: Space Science
subject: Physical Sciences not elsewhere classified
subject: Microbiology
subject: FOS: Biological sciences
subject: Cell Biology
subject: Biotechnology

description: Bacterial flagellar system (BFS) was the primary example of a purported ‘rotary-motor’ functionality in a natural assembly. This mandates the translation of a circular motion of components inside into a linear displacement of the cell body outside, which is supposedly orchestrated with the following features of the BFS: (i) A chemical/electrical differential generates proton motive force (<i>pmf</i>, including a trans-membrane potential, TMP), which is electro-mechanically transduced by inward movement of protons via BFS. (ii) Membrane-bound proteins of BFS serve as stators and the slender filament acts as an external propeller, culminating into a hook-rod that pierces the membrane to connect to a ‘broader assembly of deterministically movable rotor’. We had disclaimed the purported <i>pmf</i>/TMP-based respiratory/photosynthetic physiology involving Complex V, which was also perceived as a ‘rotary machine’ earlier. We pointed out that the murburn redox logic was operative therein. We pursue the following similar perspectives in BFS-context: (i) Low probability for the evolutionary attainment of an ordered/synchronized teaming of about two dozen types of proteins (assembled across five-seven distinct phases) towards the singular agendum of rotary motility. (ii) Vital redox activity (not the gambit of <i>pmf/</i>TMP!) powers the molecular and macroscopic activities of cells, including flagella. (iii) Flagellar movement is noted even in ambiances lacking/countering the directionality mandates sought by <i>pmf</i>/TMP. (iv) Structural features of BFS lack component(s) capable of harnessing/achieving <i>pmf</i>/TMP and functional rotation. A viable murburn model for conversion of molecular/biochemical activity into macroscopic/mechanical outcomes is proposed herein for understanding BFS-assisted motility.
HIGHLIGHTSThe motor-like functionalism of bacterial flagellar system (BFS) is analyzedProton/Ion-differential based powering of BFS is unviable in bacteriaUncouplers-sponsored effects were misinterpreted, resulting in a detour in BFS researchThese findings mandate new explanation for nano-bio-mechanical movements in BFSA minimalist murburn model for the bacterial flagella-aided movement is proposed The motor-like functionalism of bacterial flagellar system (BFS) is analyzed Proton/Ion-differential based powering of BFS is unviable in bacteria Uncouplers-sponsored effects were misinterpreted, resulting in a detour in BFS research These findings mandate new explanation for nano-bio-mechanical movements in BFS A minimalist murburn model for the bacterial flagella-aided movement is proposed Communicated by Ramaswamy H. Sarma