A structure-based model of the chromosomal cohesin complex, accompanied by molecular-mechanistic simulations, explains cohesin's key role in topologically entrapping DNA, as well as its ability to alternatively extrude DNA loops.
‘Optical tweezers’ measurements of single ribosomes and single mRNA molecules show that the translation rate depends exponentially on the applied force, and suggests that the ribosome functions as a Brownian ratchet.
By distributing receptor-binding and receptor-destroying proteins asymmetrically on their surface, filamentous influenza A virus particles create a Brownian ratchet that facilitates their passage through mucus.
Quantification of all the major on- and off-pathway kinetic parameters in the transcription elongation cycle reveals that RNA polymerase II translocates slowly in a linear, non-branched Brownian ratchet mechanism.
Structural analysis of the ATP synthase – in combination with evolutionary covariance analysis – reveals the fold of the a subunit and shows that the enzyme can adopt several different conformations, which support the Brownian ratchet model for generating rotation.
Carboxysomes, the carbon-fixation machinery of cyanobacteria, are equidistantly-positioned by dynamic gradients of the protein McdA on the nucleoid that emerge through interaction with a previously unidentified carboxysome factor, McdB.