DS-18 system

traitmech:000441 · CLASS · PROPOSED

A phage defense system in which an organism possesses the single-gene DefensePredictor-discovered system 18 locus cataloged as working transcriptional unit 6602 and whose plasmid expression in E. coli MG1655 reduced bacteriophage plaquing.

Trait evidence (8)

DOI:10.1126/science.adv7924
To test for anti-phage defense, we placed each TU with its predicted native promoter region on a low-copy number plasmid in E. coli MG1655 and challenged these strains with a panel of 24 diverse E. coli phages (Fig. 3; fig. S2). In total, 42 (45% of 94) of the cloned TUs produced smaller plaque sizes or reduced the efficiency of plating (EOP) at least ten-fold relative to an empty vector control strain

DeWeirdt et al. experimentally validated 42 predicted transcriptional units as phage-defense systems in E. coli.
DOI:10.1126/science.adv7924
We refer to these validated TUs as DefensePredictor discovered systems (DSs), with genes in multi-gene TUs denoted by an alphabetical suffix, e.g., DS-8A is the first gene of DS-8.

DeWeirdt et al. name validated transcriptional units as DefensePredictor discovered systems.
https://pmc-oa-opendata.s3.amazonaws.com/PMC13092281.1/NIHMS2163519-supplement-Table_S6.xlsx
6602 NZ_QOWV01000002.1 GCF_003334785.1 - True False False True DefensePredictor hits 550816 551577 hypothetical protein WP_021529611.1 11.52849398343986 1.909829572490831 True True Remote defense homolog DS-18

The final Science supplementary Table S6 maps working_id 6602 to DS_name DS-18, marks the cloned transcriptional unit as defensive, and records NZ_QOWV01000002.1 positions 550816-551577 with product accession WP_021529611.1.
https://pmc-oa-opendata.s3.amazonaws.com/PMC13092281.1/NIHMS2163519-supplement-Table_S7.xlsx
Candy 6.2 pLAND 24-07-17_AAA2_VPUS_VAME_EV.png 50000000 6602 24-07-24 24-07-24_6602_TRNA_SC24_2CMP.png 2 10 1000 4.698970004336019 True LB 37

The final Science supplementary Table S7 reports a 6602 assay row with a Candy phage readout and a -log(EOP) value of 4.699.
https://pmc-oa-opendata.s3.amazonaws.com/PMC13092281.1/NIHMS2163519-supplement-Table_S8.xlsx
6602.0 DS-18 True

The final Science supplementary Table S8 maps working identifier 6602 to replicated display name DS-18.
https://pmc-oa-opendata.s3.amazonaws.com/PMC13092281.1/NIHMS2163519-supplement-Table_S8.xlsx
6602 1.0 253.0 WP_021529611.1 PDDEXK PF15516.11 BpuSI_N ; BpuSI N-terminal domain hhpred_6067831.hhr 99.0 197.0 0.9417 2024-07-28 00:00:00 54-56 41.0

The final Science supplementary Table S8 reports a PDDEXK HHpred hit for WP_021529611.1 in 6602.
https://raw.githubusercontent.com/mdmparis/defense-finder-models/afb0e5a8b466be53586b13266f5d38d98c3ac268/List_system_article.md
| DS-18 | 10\.1101/2025\.01\.08\.631726 | DefensePredictor: A machine learning model to discover novel prokaryotic immune systems |

The pinned DefenseFinder article registry maps the DS-18 source key to the preprint DOI for the DeWeirdt et al. DefensePredictor study, which has since been published in Science.
https://raw.githubusercontent.com/mdmparis/defense-finder-models/afb0e5a8b466be53586b13266f5d38d98c3ac268/Liste_hmm_system.md
| DS-18__DS-18 | | DS-18 | Custom | 30 |

The pinned DefenseFinder HMM inventory records DS-18__DS-18 as a custom DS-18 profile.

DS-18 locus reduces bacteriophage plaquing

Conservative system-level sketch linking the single-gene DS-18 locus to reduced bacteriophage plaquing without resolving DS-18 component function or molecular output.

NONMECHANISTIC · The graph captures DS-18 as the validated 6602 transcriptional unit with one product accession, one PDDEXK HHpred-domain row, and one DefenseFinder DS-18 profile row. It does not assert native host breadth, exact profile-to-protein correspondence, DS-18 molecular activity, trigger, substrate, phage breadth, or DefenseFinder rule-level detection criteria.

Edge evidence

DS-18 locus contributes to reduced bacteriophage plaquing RO:0002326
The DS-18/6602 locus contributes to reduced bacteriophage plaquing in heterologous E. coli MG1655 plasmid-expression assays.
- DOI:10.1126/science.adv7924 To test for anti-phage defense, we placed each TU with its predicted native promoter region on a low-copy number plasmid in E. coli MG1655 and challenged these strains with a panel of 24 diverse E. coli phages (Fig. 3; fig. S2). In total, 42 (45% of 94) of the cloned TUs produced smaller plaque sizes or reduced the efficiency of plating (EOP) at least ten-fold relative to an empty vector control strain DeWeirdt et al. describe the plasmid-based phage challenge used to validate predicted transcriptional units.
- https://pmc-oa-opendata.s3.amazonaws.com/PMC13092281.1/NIHMS2163519-supplement-Table_S6.xlsx 6602 NZ_QOWV01000002.1 GCF_003334785.1 - True False False True DefensePredictor hits 550816 551577 hypothetical protein WP_021529611.1 11.52849398343986 1.909829572490831 True True Remote defense homolog DS-18 The final Science supplementary Table S6 maps working_id 6602 to DS_name DS-18, marks the cloned transcriptional unit as defensive, and records NZ_QOWV01000002.1 positions 550816-551577 with product accession WP_021529611.1.
- https://pmc-oa-opendata.s3.amazonaws.com/PMC13092281.1/NIHMS2163519-supplement-Table_S7.xlsx Candy 6.2 pLAND 24-07-17_AAA2_VPUS_VAME_EV.png 50000000 6602 24-07-24 24-07-24_6602_TRNA_SC24_2CMP.png 2 10 1000 4.698970004336019 True LB 37 The final Science supplementary Table S7 reports a 6602 assay row with a Candy phage readout and a -log(EOP) value of 4.699.
- https://pmc-oa-opendata.s3.amazonaws.com/PMC13092281.1/NIHMS2163519-supplement-Table_S8.xlsx 6602.0 DS-18 True The final Science supplementary Table S8 maps working identifier 6602 to replicated display name DS-18.
- https://raw.githubusercontent.com/mdmparis/defense-finder-models/afb0e5a8b466be53586b13266f5d38d98c3ac268/Liste_hmm_system.md | DS-18__DS-18 | | DS-18 | Custom | 30 | The pinned DefenseFinder HMM inventory records DS-18__DS-18 as a custom DS-18 profile.
reduced bacteriophage plaquing confers DS-18 system METPO:2007700
DS-18-mediated phage plaquing reduction realizes the DS-18 system trait.
- https://pmc-oa-opendata.s3.amazonaws.com/PMC13092281.1/NIHMS2163519-supplement-Table_S6.xlsx 6602 NZ_QOWV01000002.1 GCF_003334785.1 - True False False True DefensePredictor hits 550816 551577 hypothetical protein WP_021529611.1 11.52849398343986 1.909829572490831 True True Remote defense homolog DS-18 The final Science supplementary Table S6 maps working_id 6602 to DS_name DS-18, marks the cloned transcriptional unit as defensive, and records NZ_QOWV01000002.1 positions 550816-551577 with product accession WP_021529611.1.
- https://pmc-oa-opendata.s3.amazonaws.com/PMC13092281.1/NIHMS2163519-supplement-Table_S7.xlsx Candy 6.2 pLAND 24-07-17_AAA2_VPUS_VAME_EV.png 50000000 6602 24-07-24 24-07-24_6602_TRNA_SC24_2CMP.png 2 10 1000 4.698970004336019 True LB 37 The final Science supplementary Table S7 reports a 6602 assay row with a Candy phage readout and a -log(EOP) value of 4.699.
- DOI:10.1126/science.adv7924 We refer to these validated TUs as DefensePredictor discovered systems (DSs), with genes in multi-gene TUs denoted by an alphabetical suffix, e.g., DS-8A is the first gene of DS-8. The DS nomenclature is used for DefensePredictor discovered systems.
DS-18 system is a phage defense system rdfs:subClassOf
DS-18 system possession is a phage-defense-system trait.
- DOI:10.1126/science.adv7924 We refer to these validated TUs as DefensePredictor discovered systems (DSs), with genes in multi-gene TUs denoted by an alphabetical suffix, e.g., DS-8A is the first gene of DS-8. DeWeirdt et al. name validated TUs as DefensePredictor discovered systems.
- https://raw.githubusercontent.com/mdmparis/defense-finder-models/afb0e5a8b466be53586b13266f5d38d98c3ac268/List_system_article.md | DS-18 | 10\.1101/2025\.01\.08\.631726 | DefensePredictor: A machine learning model to discover novel prokaryotic immune systems | The pinned DefenseFinder article registry maps the DS-18 source key to the preprint DOI for the DeWeirdt et al. DefensePredictor study, which has since been published in Science.

Provenance

Identifier source: TraitMech local identifier
Definition source: DOI:10.1126/science.adv7924

Parent traits (1)

phage defense system traitmech:000209

Synonyms (3)

DS-18 EXACT_SYNONYM · DOI:10.1126/science.adv7924
6602 RELATED_SYNONYM · https://pmc-oa-opendata.s3.amazonaws.com/PMC13092281.1/NIHMS2163519-supplement-Table_S6.xlsx
DS-18__DS-18 RELATED_SYNONYM · https://raw.githubusercontent.com/mdmparis/defense-finder-models/afb0e5a8b466be53586b13266f5d38d98c3ac268/Liste_hmm_system.md

kg-microbe context

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

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 DS-18 native host breadth, exact profile-to-protein mapping, component chemistry, sensitive-phage breadth, molecular output, and rule-level DefenseFinder criteria before minting narrower DS-18 mechanism children.

KNOWLEDGE GAP OPEN ds-18-defensefinder-model-gap · raised by codex · 2026-09-28

Attached to causal_graphs#ds_18_locus_reduces_phage_plaquing

DeWeirdt et al. support DS-18 as the defensive 6602 transcriptional unit and final Science Tables S6/S7/S8 map it to product accession WP_021529611.1, a Candy phage readout, display name DS-18, and a PDDEXK HHpred row. The pinned DefenseFinder HMM inventory records one DS-18 custom profile row. The pinned rules table has no DS-18 row, and the first-pass record does not resolve native host breadth, phage breadth, direct profile-to-protein correspondence, PDDEXK nuclease activity, molecular output, or endogenous DS-18 activity.

Evidence

DOI:10.1126/science.adv7924
We refer to these validated TUs as DefensePredictor discovered systems (DSs), with genes in multi-gene TUs denoted by an alphabetical suffix, e.g., DS-8A is the first gene of DS-8.
https://pmc-oa-opendata.s3.amazonaws.com/PMC13092281.1/NIHMS2163519-supplement-Table_S6.xlsx
6602 NZ_QOWV01000002.1 GCF_003334785.1 - True False False True DefensePredictor hits 550816 551577 hypothetical protein WP_021529611.1 11.52849398343986 1.909829572490831 True True Remote defense homolog DS-18
https://pmc-oa-opendata.s3.amazonaws.com/PMC13092281.1/NIHMS2163519-supplement-Table_S7.xlsx
Candy 6.2 pLAND 24-07-17_AAA2_VPUS_VAME_EV.png 50000000 6602 24-07-24 24-07-24_6602_TRNA_SC24_2CMP.png 2 10 1000 4.698970004336019 True LB 37
https://pmc-oa-opendata.s3.amazonaws.com/PMC13092281.1/NIHMS2163519-supplement-Table_S8.xlsx
6602.0 DS-18 True
https://pmc-oa-opendata.s3.amazonaws.com/PMC13092281.1/NIHMS2163519-supplement-Table_S8.xlsx
6602 1.0 253.0 WP_021529611.1 PDDEXK PF15516.11 BpuSI_N ; BpuSI N-terminal domain hhpred_6067831.hhr 99.0 197.0 0.9417 2024-07-28 00:00:00 54-56 41.0
https://raw.githubusercontent.com/mdmparis/defense-finder-models/afb0e5a8b466be53586b13266f5d38d98c3ac268/List_system_article.md
| DS-18 | 10\.1101/2025\.01\.08\.631726 | DefensePredictor: A machine learning model to discover novel prokaryotic immune systems |
https://raw.githubusercontent.com/mdmparis/defense-finder-models/afb0e5a8b466be53586b13266f5d38d98c3ac268/Liste_hmm_system.md
| DS-18__DS-18 | | DS-18 | Custom | 30 |
https://raw.githubusercontent.com/mdmparis/defense-finder-models/afb0e5a8b466be53586b13266f5d38d98c3ac268/DefenseFinder_rules.tsv

Curation history

2026-09-28T18:54:30Z · MINTED_TRAITMECH_ID · codex
Minted DS-18 system as a DOI-backed GENOMICS TraitRecord under phage defense system after an ignored-and-hidden duplicate review found no exact live TraitMech, METPO, history, or prior proposal record; kept the graph at 6602 transcriptional-unit level because PDDEXK chemistry and rule rows remain unresolved, and proposals/metpo_traitmech_v318 reserves the replacement placeholder.
2026-09-28T18:54:31Z · REVIEW_CANONICAL_EXAMPLE_EVIDENCE_GAP · codex
Reviewed DS-18 system canonical_examples and left them empty because DeWeirdt et al. directly support cloned 6602 assays in E. coli MG1655 and a DefenseFinder DS-18 model, but not a direct named native microbial isolate exemplar with experimentally verified endogenous DS-18 activity. No paid research was used.