Macromolecule diffusion and confinement in prokaryotic cells

Characterization of the motion of membrane proteins using high-speed atomic force microscopy

“…For example, crowding has previously been identified as a possible source of limited diffusion 14 but was exclusively examined with modelling 15 . With HS-AFM, a technique that allows for the explicit observation of the environment of a moving protein, we can now experimentally assess the effect of crowding for the first time.…”

A propagating ATPase gradient drives transport of surface-confined cellular cargo

“…Instead, the plasmid diffused away from the carpet once all tether points, i.e., SopBSopA interactions, were released. We hypothesized our flow cell lacked the surface confinement needed to maintain contact between the plasmid and the DNA carpet, as the narrow gap between the nucleoid and the inner membrane in vivo would confine the plasmid to the nucleoid surface (13).…”

Localized mRNA translation and protein association

“…The corresponding "diffusion-andcapture" mechanism implies that a protein or RNA diffuses until it encounters its binding site [14]. (iii) Concerning bacteria, one can note that despite the absence of compartments, their structure is heterogeneous, and proteins (or RNAs) can be excluded or enriched at positions like the nucleoid or pole [17]. According to (ii) and (iii), the rate of RNA or protein diffusion is not of central importance, because the factors behind localization are related to thermodynamics.…”

“…According to (ii) and (iii), the rate of RNA or protein diffusion is not of central importance, because the factors behind localization are related to thermodynamics. (iv) Two other general factors behind protein and RNA localization appear to be slow diffusion of these species (due to macromolecular crowding [16,17]) and the ability of some mRNAs and/or proteins to aggregate and form immobile or slowly mobile complexes [11,14].…”