Druantia type IV system

Trait evidence (3)

• DOI:10.1093/nar/gkab883

  the Druantia-like system lacks the type II requisite DruM and DruG proteins, instead encoding a hypothetical protein

  Payne et al., Results and Figure 2C: the recurring type-IV architecture contains DruE and DruF together with the newly named DruL, instead of the type-II DruM/G components. This is a literature-defined system-possession class, not an individual profile. The study tests Zorya III, Hachiman II and Lamassu II, not Druantia IV. Its computational classification does not demonstrate type-IV phage resistance or DruL chemistry.

• https://raw.githubusercontent.com/mdmparis/defense-finder-models/afb0e5a8b466be53586b13266f5d38d98c3ac268/definitions/DefenseFinder/Druantia/Druantia_IV.xml

  <gene name="Druantia_IV__DruL" presence="mandatory"/>

  Pinned DefenseFinder XML, retrieved 2026-10-03: three mandatory slots, both minimum counts 3, inter_gene_max_space 1. DruL is mandatory; DruE_1 accepts DruE_2, DruE_3 or DruE4 exchangeables, and the Druantia-II DruF slot accepts DruF4. There are no forbidden genes: a call does not establish absence of DruM/G. Check full locus context before assigning the literature-defined architecture. Detection does not establish functional defense.

• https://raw.githubusercontent.com/padlocbio/padloc-db/9e380165633a8d6aef93b5a164cea0f3359bd33f/sys/druantia_type_IV.yaml

  minimum_core: 3 minimum_total: 3 core_genes: - DruE4 - DruF4 - DruL4

  Pinned PADLOC rule, retrieved 2026-10-03: three required core genes, maximum_separation 3, force_strand FALSE. DruK is secondary, not a required defining component. The prohibited list is NA, so the detector does not test the biological absence of DruM/G. A missing hit or incomplete assembly cannot establish that absence. These are computational constraints, not experimental component essentiality or type-IV mechanism evidence.