General description: Proteins from ECF281 have homology to original groups ECF20 (10.45%) and ECF113 (0.85%), and are present in Firmicutes (41.44%), Actinobacteria (23.42%), Deinococcus-Thermus (18.92%) from genus Deinococcus and Proteobacteria (16.22%).
Anti-σ factor: Most of the subgroups contain putative AS factors with one TM helix (79.69%) and a zinc-finger encoded in +1. In subgroups ECF281s3 and ECF281s4, the putative AS factor could be fused to a DUF4349. Instead, subgroups ECF281s1, ECF281s5, ECF281s7 and ECF281s10 do not contain AS factors in their genomic context. It is likely that the AS factors of these subgroups are encoded somewhere else in the genome.
Genomic context conservation: Other proteins conserved are a heavy-metal resistance protein (+2 of ECF281s2), a tRNA-dihydrouridine synthase (-1 of ECF281s6), and a protein from family FUN14 (-1 of ECF281s5), which appears in Eubacteria, Archaea and Eukaryotes and is involved in mitophagy induced by hypoxia in mammalian cells (Liu et al., 2012).
Promoter motif conservation: Predicted target promoter motifs are conserved and contain GGAACTT in -35 and a less conserved GTCTAA in -10. This motif is similar, but not identical, to the target promoter motif in the original group ECF20 (Rhodius et al., 2013).
Summary: Members of ECF281 are regulated by zinc-finger AS factors with one transmembrane helix encoded in +1. Members of ECF281 could be involved in response to heavy metals and their detoxification. This function inherits from original ECF20 (Staroń et al., 2009), even though the only characterized member of original ECF20 is now classified against ECF291.
Number of representative ECFs: 314
Number of non-redundant ECFs: 354
Sequences with C-terminal extension: 0.00%
Sequences with N-terminal extension: 1.13%
Overrepresented phylum: Firmicutes [31.53%]