Browse anti-prokaryotic immune system families by Defense system

AD families AD genes Defense system CLAN ID Phages/MGEs References Description
APIS003 ArdA restriction-modification (RM) CLAN004 plasmid pKM101 of E. coli PMID:2989658 DNA mimetics, i.e. structurally and electrostatically imitate the B-form of DNA and thus function as competitive inhibitors of restriction enzymes.
APIS007 KlcA restriction-modification (RM) CLAN003 IncP-1b plasmid of Bordetella pertussis PMID:20007596 ArdB and KlcA act as anti-restriction proteins and inhibit the four main families of Type I RM systems in vivo.
APIS009 Ral restriction-modification (RM) CLAN013 Lambda of E. coli PMID:3023633 Ral of phage λ can activate the activity of the MTase and thereby accelerate protection of the phage DNA.
APIS010 Ocr restriction-modification (RM);bacteriophage exclusion (BREX) CLAN020 T7 of E. coli PMID:32338761 329108 12235377 11804597 Ocr physically associates with BrxX methyltransferase to neutralizes their ability to both methylate and exclude incoming phage DNA. Ocr structurally mimics the DNA phosphate backbone and interacts directly with EcoKI (both the MTase and REase domain of this type I R–M enzyme), thereby interfering with the activity of this system.
APIS015 IpII restriction-modification (RM) CLAN010 T4 of E. coli Silas et al., 2023 T4 internal-protein, a T2-restricting defense system was disabled by IpII. IpII restored T2 and T6 plaquing but did not further enhance T4 infection.
APIS018 Arn restriction-modification (RM) CLAN011 T4 of E. coli PMID:25118281 T4 phage protein Arn (Anti restriction nuclease) was identified as an inhibitor of the restriction enzyme McrBC.
APIS021 SieA restriction-modification (RM) CLAN005 Salmonella phage P22 Silas et al., 2023 Superinfection exclusion.
APIS030 DarB restriction-modification (RM) CLAN009 P1 of E. coli PMID:3029954 Bind to phage DNA, thereby masking type I R–M recognition sites and preventing degradation of phage DNA.
APIS031 DarA restriction-modification (RM) CLAN006 P1 of E. coli PMID:3029954 Bind to phage DNA, thereby masking type I R–M recognition sites and preventing degradation of phage DNA.
APIS033 Lar restriction-modification (RM) CLAN007 Escherichia phage vB_EcoP_24B PMID:7476171 Lar is functionally similar to RaI, is able to alleviate restriction and enhance modification by EcoKI. And the nucleotide sequences of their genes share 47% identity, indicating a common origin.
APIS055 CLAN003 Pseudomonas phage Churro
APIS077 CLAN020 Proteus phage PM 116
APIS085 CLAN020 Escherichia phage T7
APIS087 CLAN020 Shigella phage ESh23
APIS090 IpI restriction-modification (RM) CLAN008 T4 of E. coli PMID:17188297 18037438 Restriction endonuclease inhibitor IpI blocks the ancestral two-component type IV R-M system and represents a third generation bacteriophage defense against restriction nucleases of the Gmr type.
APIS091 HOS17_gp01 restriction-modification (RM);bacteriophage exclusion (BREX) CLAN015 T3 of E. coli Andriianov et al., 2023 T3 encodes a SAMase that circumvents the SAM-dependent Type I R-M defence of the host E. coli through cleavage of S-adenosyl-methionine (SAM). SAMase also allows T3 to evade BREX defence.
APIS093 CLAN015 Pantoea phage vB_PagP-SK1
ArdB ArdB restriction-modification (RM) CLAN003 plasmid pKM101 of E. coli PMID:8393008 Like ArdA, ArdB efficiently inhibits restriction by members of the three known families of type I systems of E. coli and only slightly affects the type II enzyme, EcoRI.
Stp Stp restriction-modification (RM) CLAN012 T4 of E. coli PMID:7791212 Stp has been implicated with activation of the anticodon nuclease and inhibition of EcoprrI restriction.