{"record":{"author":{"account_ref":null,"orcid":null},"builds_on":[],"content_schema":"pubphys.content.revision/1","content_sha256":"94838abbb2aa8a81f8fa231ca51263a8189930a36c7f19646147ce536aeb330c","created":"2026-10-03T07:17:57Z","files":[],"origin":{"assisted_by":[],"kind":"seed"},"parents":["5475cf5dc5b1a72283d26dc95dc6e00d7ea4e00096a7c6492e409a1816eeb011"],"salt":"30f69c4dc1b307ac01c08ce97a2ebbdb11d833ab6f4d4a785d6d000ce99c17fa","schema":"pubphys.record/2","site":"pubphys.com","target":null,"type":"revision"},"content":{"answer_type":"mechanism","assisted_by":[],"external_id":"bio.cellular-sensing.ecoli-information-gap","kind":"phenomenon","literature_status":"open","n":"1","parents":[],"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.","posed_since":"2021","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.","problem_ref":null,"references":"","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.","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.","title":"Why E. coli encodes far less information than molecule counting allows","topic_ref":"162aec31a0a35d10d7205c0113216cb9f810fe4d327304e36437346a256186d4"},"attested":{"attestation":{"batch":null,"client_id":null,"id_token_sha256":null,"kind":"platform"},"record_hash":"abf21273f189e1ce606179068c0bc2a40437eee4a3925c1428590acba910dc1e","schema":"pubphys.attested/1"},"envelope":{"attested_hash":"39b59e6240232301ea4c7c4ebc23925c13b1bee20f696a2c7e8cd3fa46252cb9","platform_signature":{"key_id":"c6afc19b31429869751f06879c75cd64ea92654423d15b44be775bf1310a60da","sig":"7MtwE4TZndLpkI6ZHs7awE50DYfH6psHfz_AvtgaSgnmSunSlTQHZ5HPkfR_LY8k2_9848uipDnpByUPv1Y7BA"},"schema":"pubphys.envelope/1"},"record_hash":"abf21273f189e1ce606179068c0bc2a40437eee4a3925c1428590acba910dc1e","leaf_index":734}