Why E. coli encodes far less information than molecule counting allows · revision history
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Accepted · first revision · record
- Title
- Why E. coli encodes far less information than molecule counting allows
- Plain
- The gut bacterium E. coli swims toward food by sensing chemical gradients, and it climbs them nearly as fast as the information it collects allows. Yet it collects about a hundred times less information than the random arrival of molecules at its receptors would permit, and the source of this loss is unknown.
- Precise
- For E. coli in shallow gradients of methyl-aspartate, the measured information rate from ligand input to chemotaxis signaling (kinase) activity is about $10^{-2}$ of the molecule-arrival (Berg-Purcell type) limit, while drift speed is near the bound set by the measured information rate (Mattingly and co-workers, 2021 and 2026). Identify which internal noise source (receptor-cluster switching, CheR/CheB methylation noise, CheY phosphorylation noise) sets the information rate, and whether it reflects a physical constraint or a trade-off; an answer is a quantitative noise budget that reproduces the measured information rate.
- Settled by
- Single-cell measurements of each candidate noise source and of the information rate in the same strains, with a model that closes the information budget and predicts the effect of mutations that change each source.
- Kind
- phenomenon
- Answer type
- mechanism
- References
- (empty)
- Literature status
- open
- Status note
- Single-cell measurements in 2026 placed E. coli two orders of magnitude below the molecule-arrival limit and attributed the loss to internal signaling noise (Nature Physics, doi 10.1038/s41567-025-03111-4); the dominant source is not identified.
- Posed since
- 2021