long Lamassu system

traitmech:000571 · CLASS · PROPOSED

A Lamassu system in which an organism possesses a locus from the long-LmuB family, characterized by longer coiled-coil regions in its SMC-like LmuB sensor than in short Lamassu systems.

Trait evidence (3)

DOI:10.1073/pnas.2519643122
two major clades, which were mainly distinguished by the length of coiled-coil regions

Results, LmuB phylogeny paragraph and Figure 1: the long family is distinguished from short Lamassu by phylogeny and structure. The approximate 800-residue total LmuB length is descriptive, not a membership cutoff.
DOI:10.1073/pnas.2519643122
one system from Bacillus cereus B4077, encoding Hydrolase-Protease effectors

The same paragraph explicitly identifies B4077 as the long-clade exception among previously validated systems. This supports strain-qualified possession, not species-wide distribution or a native-host phage-resistance measurement.
https://pmc-oa-opendata.s3.amazonaws.com/PMC12663957.1/pnas.2519643122.sd01.xlsx
ACCA003.0722.00003.C001 ACCA003.0722.00003.C001_02431 Lamassu__LmuB_Long ACCA003.0722.00003.C001 ACCA003.0722.00003.C001_02432 Lamassu__LmuC_Clade_VII ACCA003.0722.00003.C001 ACCA003.0722.00003.C001_02433 Lamassu__LmuA_Cap4_III

Dataset S1, S3_Lamassu_Detection!A58:C60, raw cells in column order. Column F assigns these rows to one ACCA003.0722.00003.C001_Lamassu_Cap4_321 call; column I reports sys_wholeness 1.0. Column C (gene_name) identifies the actual long-LmuB hit, unlike column L (hit_gene_ref), which can name the long model slot for short hits. These are computational locus observations, not an experimental antiviral phenotype or a family-membership rule.

Provenance

Identifier source: TraitMech local identifier
Definition source: DOI:10.1073/pnas.2519643122

Parent traits (1)

Lamassu system traitmech:000232

Synonyms (1)

long Lamassu EXACT_SYNONYM · DOI:10.1073/pnas.2519643122

kg-microbe context

No kg-microbe node embedding matched this record in the 2026-04-25 deepwalk.

Canonical examples (1)

Organisms cited as exemplars of this trait. Taxon ids are NCBITaxon and link out to the NCBI record.

Bacillus cereus NCBITaxon:1396 DOI:10.1073/pnas.2519643122 Strain B4077 is the source of the Hydrolase-Protease system assigned to the long family by Haudiquet et al. The species identifier anchors this strain-qualified example; no genome assembly, universal species possession, or native-host phage-resistance phenotype is inferred.

Discussions and Knowledge Gaps (1)

Open questions attached to this trait. Seeded by just knowledge-gap-scan and curated; see the corpus-wide index.

Resolve borderline loci and long-family activation mechanisms.

KNOWLEDGE GAP OPEN long-lamassu-classification-and-mechanism-scope · raised by codex · 2026-10-03

Not yet attached to a section of this record — a curator sets attaches_to (e.g. causal_graphs#some_edge) so the gap shows beside the mechanism it concerns.

Long denotes a phylogenetic and structural family, not an isolated protein, a fixed amino-acid threshold, an effector name, or the component-number type II category. A raw long-profile hit alone does not settle membership of an ambiguous locus. The published detection sheet uses gene_name for actual hits and hit_gene_ref for potentially exchangeable model slots; these fields must not be conflated. Hydrolase-Protease spans both length families; the legacy FMO record's detector-defined scope and SMEK's long-profile exception need separate reconciliation before reparenting. No universal effector chemistry, LmuC requirement, zinc-hook count, or stoichiometry is imposed. The experimentally resolved short Vc-Cap4 activation mechanism is not transferred to this family. Native-host activity, accession-level protein anchors and family-wide activation remain open, so no causal mechanism graph is asserted.

Curation history

2026-10-03T14:29:24Z · MINTED_TRAITMECH_ID · codex
Added the literature-defined long Lamassu family with exact primary paper and dataset snippets and a strain-qualified B4077 example. Distinguished actual profile hits from model slots without adopting a length cutoff or transferring short-family mechanisms. Ignored-and-hidden searches found no exact record or METPO term. Reserved METPO:1052500 in proposals/metpo_traitmech_v448; left sibling hierarchies unchanged pending their own scope reconciliation.