DART_ECO27
ID DART_ECO27 Reviewed; 218 AA.
AC B7UP20;
DT 03-AUG-2022, integrated into UniProtKB/Swiss-Prot.
DT 10-FEB-2009, sequence version 1.
DT 03-AUG-2022, entry version 42.
DE RecName: Full=DNA ADP-ribosyl transferase {ECO:0000303|PubMed:32023456};
DE Short=DarT {ECO:0000303|PubMed:32023456};
DE EC=2.4.2.- {ECO:0000269|PubMed:32023456};
DE AltName: Full=Toxin DarT {ECO:0000303|PubMed:32023456};
GN Name=darT {ECO:0000303|PubMed:32023456};
GN OrderedLocusNames=E2348C_1093 {ECO:0000312|EMBL:CAS08641.1};
OS Escherichia coli O127:H6 (strain E2348/69 / EPEC).
OC Bacteria; Proteobacteria; Gammaproteobacteria; Enterobacterales;
OC Enterobacteriaceae; Escherichia.
OX NCBI_TaxID=574521;
RN [1] {ECO:0000312|EMBL:CAS08641.1}
RP NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC STRAIN=E2348/69 / EPEC;
RX PubMed=18952797; DOI=10.1128/jb.01238-08;
RA Iguchi A., Thomson N.R., Ogura Y., Saunders D., Ooka T., Henderson I.R.,
RA Harris D., Asadulghani M., Kurokawa K., Dean P., Kenny B., Quail M.A.,
RA Thurston S., Dougan G., Hayashi T., Parkhill J., Frankel G.;
RT "Complete genome sequence and comparative genome analysis of
RT enteropathogenic Escherichia coli O127:H6 strain E2348/69.";
RL J. Bacteriol. 191:347-354(2009).
RN [2]
RP FUNCTION AS A TOXIN, FUNCTION AS AN ADP-RIBOSYL TRANSFERASE, SUBUNIT, AND
RP MUTAGENESIS OF GLY-49 AND GLU-170.
RC STRAIN=E2348/69 / EPEC;
RX PubMed=32023456; DOI=10.1016/j.celrep.2020.01.014;
RA Lawaree E., Jankevicius G., Cooper C., Ahel I., Uphoff S., Tang C.M.;
RT "DNA ADP-Ribosylation Stalls Replication and Is Reversed by RecF-Mediated
RT Homologous Recombination and Nucleotide Excision Repair.";
RL Cell Rep. 30:1373-1384(2020).
RN [3]
RP FUNCTION AS A TOXIN, FUNCTION AS AN ADP-RIBOSYL TRANSFERASE, AND
RP MUTAGENESIS OF GLY-49 AND GLU-170.
RC STRAIN=E2348/69 / EPEC;
RX PubMed=34408320; DOI=10.1038/s41586-021-03825-4;
RA Schuller M., Butler R.E., Ariza A., Tromans-Coia C., Jankevicius G.,
RA Claridge T.D.W., Kendall S.L., Goh S., Stewart G.R., Ahel I.;
RT "Molecular basis for DarT ADP-ribosylation of a DNA base.";
RL Nature 596:597-602(2021).
CC -!- FUNCTION: Toxic component of a hybrid type II/IV toxin-antitoxin (TA)
CC system. ADP-ribosylates ssDNA in the sequence TTT/TCT. Its toxic effect
CC is neutralized by cognate antitoxin DarG (PubMed:32023456). May target
CC ssDNA loops during DNA replication, probably modifies thymidine
CC (Probable). Wild-type protein cannot be expressed at low levels in the
CC absence of its cognate antitoxin, but a mutant protein (G49D) can be
CC expressed, which slows growth, rapidly inhibits DNA replication, and
CC induces RecA expression and the SOS response (PubMed:32023456). The
CC slow growth phenotype can be suppressed by cognate antitoxin DarG. Has
CC no activity on dsDNA in vitro (PubMed:32023456). In vivo ADP-
CC ribosylates genomic DNA (gDNA) (PubMed:34408320). Genetic data strongly
CC suggests ADP-ribosylation by DarT probably generates ssDNA gaps that
CC are repaired by the RecFOR-mediated homologous recombination pathway
CC (RuvAB, RecG) and resolved by RuvC. In some cases these gaps probably
CC migrate into dsDNA, where they are resolved by nucleotide excision
CC repair (NER) detected by UvrAB, excised by UvrC, removed by UvrD, and
CC repaired by Pol I and ligase. Other pathways may also be involved in
CC ADP-ribosylation removal from DNA (Probable).
CC {ECO:0000269|PubMed:32023456, ECO:0000269|PubMed:34408320,
CC ECO:0000305|PubMed:32023456}.
CC -!- CATALYTIC ACTIVITY:
CC Reaction=a thymidine in DNA + NAD(+) = an N-(ADP-alpha-D-ribosyl)-
CC thymidine in DNA + H(+) + nicotinamide; Xref=Rhea:RHEA:71651,
CC Rhea:RHEA-COMP:13556, Rhea:RHEA-COMP:18051, ChEBI:CHEBI:15378,
CC ChEBI:CHEBI:17154, ChEBI:CHEBI:57540, ChEBI:CHEBI:137386,
CC ChEBI:CHEBI:191199;
CC PhysiologicalDirection=left-to-right; Xref=Rhea:RHEA:71652;
CC Evidence={ECO:0000269|PubMed:32023456, ECO:0000269|PubMed:34408320};
CC -!- SUBUNIT: Interacts with DarG, primarily via the C-terminus of DarG
CC (tested with DarT mutant G49D), which probably sequesters DarT and
CC inhibits it. {ECO:0000269|PubMed:32023456}.
CC -!- DOMAIN: The NAD(+)-binding element stabilizes the ADP-ribosylating
CC turn-turn (ARTT) loop which confers substrate specificity; both domains
CC contribute to ssDNA-binding. {ECO:0000250|UniProtKB:A0A0B0SG80}.
CC -!- SIMILARITY: Belongs to the DarT ADP-ribosyltransferase family.
CC {ECO:0000305}.
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DR EMBL; FM180568; CAS08641.1; -; Genomic_DNA.
DR RefSeq; WP_000312835.1; NC_011601.1.
DR EnsemblBacteria; CAS08641; CAS08641; E2348C_1093.
DR KEGG; ecg:E2348C_1093; -.
DR HOGENOM; CLU_113641_0_0_6; -.
DR OMA; HDYVPFY; -.
DR Proteomes; UP000008205; Chromosome.
DR InterPro; IPR029494; DarT.
DR Pfam; PF14487; DarT; 1.
PE 1: Evidence at protein level;
KW DNA-binding; Glycosyltransferase; Nucleotidyltransferase;
KW Toxin-antitoxin system; Transferase.
FT CHAIN 1..218
FT /note="DNA ADP-ribosyl transferase"
FT /id="PRO_0000456048"
FT DOMAIN 17..217
FT /note="DarT"
FT /evidence="ECO:0000255"
FT REGION 41..59
FT /note="NAD(+)-binding element"
FT /evidence="ECO:0000250|UniProtKB:A0A0B0SG80"
FT REGION 123..170
FT /note="ADP-ribosylating turn-turn loop"
FT /evidence="ECO:0000250|UniProtKB:A0A0B0SG80"
FT ACT_SITE 57
FT /note="Proton acceptor"
FT /evidence="ECO:0000250|UniProtKB:A0A0B0SG80"
FT ACT_SITE 170
FT /evidence="ECO:0000250|UniProtKB:A0A0B0SG80"
FT BINDING 18..20
FT /ligand="NAD(+)"
FT /ligand_id="ChEBI:CHEBI:57540"
FT /evidence="ECO:0000250|UniProtKB:A0A0B0SG80"
FT BINDING 57
FT /ligand="NAD(+)"
FT /ligand_id="ChEBI:CHEBI:57540"
FT /evidence="ECO:0000250|UniProtKB:A0A0B0SG80"
FT MUTAGEN 49
FT /note="G->D: Decreased levels of ssDNA ADP-ribosylation,
FT decreased viability of E.coli without endogenous darTG
FT operon, impedes DNA replication, induces RecA expression.
FT Still ADP-ribosylates gDNA in vivo."
FT /evidence="ECO:0000269|PubMed:32023456,
FT ECO:0000269|PubMed:34408320"
FT MUTAGEN 170
FT /note="E->A: Nearly complete loss of ssDNA ADP-
FT ribosylation, not toxic in situ, no effect on DNA
FT replication, no RecA induction. No ADP-ribosylation of gDNA
FT in vivo."
FT /evidence="ECO:0000269|PubMed:32023456,
FT ECO:0000269|PubMed:34408320"
SQ SEQUENCE 218 AA; 25277 MW; 30DE527BCB2A04C6 CRC64;
MAYDYSASLN PQKALIWRIV HRDNIPWILD NGLHCGNSLV QAENWINIGN PELIGKRAGH
PVPVGTGGTL HDYVPFYFTP FSPMLMNIHS GRGGIKRRPN EEIVILVSNL RNVAAHDVPF
VFTDSHAYYN WTNYYTSLNS LDQIDWPILQ ARDFRRDPDD PAKFERYQAE ALIWQHCPIS
LLDGIICYSE EVRLQLEQWL FQRNLTMSVH TRSGWYFS
