Pulling cargo increases the precision of molecular motor progress

Aidan I Brown; David A Sivak

doi:10.1209/0295-5075/126/40004

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arXiv · 1805.08917

Pulling cargo increases the precision of molecular motor progress

Aidan I Brown·David A Sivak

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Abstract

Biomolecular motors use free energy to drive a variety of cellular tasks, including the transport of cargo, such as vesicles and organelles. We find that the widely-used `constant-force' approximation for the effect of cargo on motor dynamics leads to a much larger variance of motor step number compared to explicitly modeling diffusive cargo, suggesting the constant-force approximation may be misapplied in some cases. We also find that, with cargo, motor progress is significantly more precise than suggested by a recent result. For cargo with a low relative diffusivity, the dynamics of continuous cargo motion---rather than discrete motor steps---dominate, leading to a new, more permissive bound on the precision of motor progress which is independent of the number of stages per motor cycle.

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Aidan I Brown, David A Sivak. 2018-05-23. Pulling cargo increases the precision of molecular motor progress. https://doi.org/10.1209/0295-5075%2F126%2F40004

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