ID   TRAI2_ECOLX             Reviewed;        1756 AA.
AC   P22706; Q51812;
DT   01-AUG-1991, integrated into UniProtKB/Swiss-Prot.
DT   01-AUG-1991, sequence version 1.
DT   02-SEP-2026, entry version 107.
DE   RecName: Full=Multifunctional conjugation protein TraI;
DE   Includes:
DE     RecName: Full=DNA relaxase TraI;
DE              EC=5.6.2.- {ECO:0000250|UniProtKB:P14565};
DE     AltName: Full=DNA nickase TraI;
DE     AltName: Full=Trans-esterase TraI;
DE   Includes:
DE     RecName: Full=DNA helicase I;
DE              EC=5.6.2.3 {ECO:0000250|UniProtKB:P14565};
DE     AltName: Full=DNA 5'-3' helicase TraI {ECO:0000305};
GN   Name=traI;
OS   Escherichia coli.
OG   Plasmid IncFII R100 (NR1), and Plasmid F.
OC   Bacteria; Pseudomonadati; Pseudomonadota; Gammaproteobacteria;
OC   Enterobacterales; Enterobacteriaceae; Escherichia.
OX   NCBI_TaxID=562;
RN   [1] {ECO:0000312|EMBL:CAA39337.1}
RP   NUCLEOTIDE SEQUENCE [GENOMIC DNA].
RC   PLASMID=IncFII R100 (NR1);
RX   PubMed=2164585; DOI=10.1016/0022-2836(90)90145-c;
RA   Yoshioka Y., Fujita Y., Ohtsubo E.;
RT   "Nucleotide sequence of the promoter-distal region of the tra operon of
RT   plasmid R100, including traI (DNA helicase I) and traD genes.";
RL   J. Mol. Biol. 214:39-53(1990).
RN   [2]
RP   NUCLEOTIDE SEQUENCE [GENOMIC DNA] OF 1747-1756.
RC   PLASMID=F;
RX   PubMed=1916281; DOI=10.1016/0378-1119(91)90469-r;
RA   Cram D.S., Loh S.M., Cheah K.C., Skurray R.A.;
RT   "Sequence and conservation of genes at the distal end of the transfer
RT   region on plasmids F and R6-5.";
RL   Gene 104:85-90(1991).
CC   -!- FUNCTION: Conjugative DNA transfer (CDT) is the unidirectional transfer
CC       of ssDNA plasmid from a donor to a recipient cell. It is the central
CC       mechanism by which antibiotic resistance and virulence factors are
CC       propagated in bacterial populations. Part of the relaxosome, which
CC       facilitates a site- and strand-specific cut at the nic site in the
CC       origin of transfer by TraI. Relaxosome formation requires binding of
CC       IHF and TraY to the oriT region, which then facilitates binding of TraI
CC       relaxase. TraI forms a covalent 5'-phosphotyrosine intermediate linkage
CC       with the nicked ssDNA. The trans-esterified single-stranded T-strand
CC       moves from the donor cell to the recipient cell in a 5'-3' direction,
CC       with the DNA helicase activity of TraI unwinding the DNA. DNA transfer
CC       occurs via the F pilus, an intercellular junction mediated by a type IV
CC       secretion system (T4SS), with TraD providing the means to link the
CC       relaxosome to the conjugative pore. The relaxase completes DNA transfer
CC       by reversing the covalent phosphotyrosine linkage, presumably
CC       recircularizing and releasing the plasmid DNA.
CC       {ECO:0000250|UniProtKB:P14565}.
CC   -!- FUNCTION: TraI encodes DNA helicase I, a highly processive single-
CC       stranded (ss)DNA-dependent ATPase, able to unwind double-stranded
CC       (ds)DNA in a 5'-3' direction (By similarity).
CC       {ECO:0000250|UniProtKB:P14565}.
CC   -!- CATALYTIC ACTIVITY:
CC       Reaction=Couples ATP hydrolysis with the unwinding of duplex DNA at the
CC         replication fork by translocating in the 5'-3' direction.;
CC         EC=5.6.2.3; Evidence={ECO:0000250|UniProtKB:P14565};
CC   -!- CATALYTIC ACTIVITY:
CC       Reaction=ATP + H2O = ADP + phosphate + H(+); Xref=Rhea:RHEA:13065,
CC         ChEBI:CHEBI:15377, ChEBI:CHEBI:15378, ChEBI:CHEBI:30616,
CC         ChEBI:CHEBI:43474, ChEBI:CHEBI:456216; EC=5.6.2.3;
CC         Evidence={ECO:0000250|UniProtKB:P14565};
CC   -!- COFACTOR:
CC       Name=Mg(2+); Xref=ChEBI:CHEBI:18420;
CC         Evidence={ECO:0000250|UniProtKB:P14565};
CC   -!- SUBUNIT: Monomer. Forms a dimer on single-stranded (ss) oriT DNA; one
CC       monomer is on the 5' side of the nic site in an open 'trans-esterase'
CC       conformation while the other monomer is on the 3' side in a closed
CC       'helicase' conformation. The open conformation subunit probably moves
CC       with DNA into the recipient cell. Part of the relaxosome, a complex
CC       composed of plasmid-encodes TraI, TraM, TraY and host-encoded IHF bound
CC       to the F plasmid origin of transfer (oriT). Directly contacts coupling
CC       protein TraD. Seems to directly contact TraM via its C-terminus.
CC       {ECO:0000250|UniProtKB:P14565, ECO:0000250|UniProtKB:Q6TDU5}.
CC   -!- SUBCELLULAR LOCATION: Cytoplasm {ECO:0000250|UniProtKB:P14565}.
CC   -!- DOMAIN: Has 4 domains; the trans-esterase domain (residues 1-306), a
CC       vestigal helicase domain (residues 315-828), the active helicase domain
CC       (residues 864-1461) and the C-terminal domain (1462-1756) (By
CC       similarity). {ECO:0000250|UniProtKB:Q6TDU5}.
CC   -!- SIMILARITY: Belongs to the TraI relaxase-helicase family.
CC       {ECO:0000305}.
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DR   EMBL; X55815; CAA39337.1; -; Genomic_DNA.
DR   EMBL; M38047; AAA98090.1; -; Genomic_DNA.
DR   PIR; S10660; BVECAI.
DR   AlphaFoldDB; P22706; -.
DR   SMR; P22706; -.
DR   GO; GO:0005737; C:cytoplasm; ISS:UniProtKB.
DR   GO; GO:0043139; F:5'-3' DNA helicase activity; ISS:UniProtKB.
DR   GO; GO:0005524; F:ATP binding; IEA:InterPro.
DR   GO; GO:0016887; F:ATP hydrolysis activity; ISS:UniProtKB.
DR   GO; GO:0003677; F:DNA binding; IEA:InterPro.
DR   CDD; cd17933; DEXSc_RecD-like; 1.
DR   CDD; cd18809; SF1_C_RecD; 1.
DR   Gene3D; 6.10.140.290; -; 1.
DR   Gene3D; 6.10.250.110; -; 1.
DR   Gene3D; 3.40.50.300; P-loop containing nucleotide triphosphate hydrolases; 1.
DR   InterPro; IPR014129; Conjug_relaxase_TraI.
DR   InterPro; IPR009767; DNA_helicase_TraI_C.
DR   InterPro; IPR027417; P-loop_NTPase.
DR   InterPro; IPR014059; TraI/TrwC_relax.
DR   InterPro; IPR040668; TraI_2B.
DR   InterPro; IPR054558; TraI_hel_assoc_DBD_N.
DR   InterPro; IPR040987; TraI_N.
DR   InterPro; IPR014862; TrwC.
DR   NCBIfam; NF041492; MobF; 1.
DR   NCBIfam; NF010263; PRK13709.1; 1.
DR   NCBIfam; NF011300; PRK14712.1; 1.
DR   NCBIfam; TIGR02686; relax_trwC; 1.
DR   NCBIfam; TIGR02760; TraI_TIGR; 1.
DR   Pfam; PF13604; AAA_30; 1.
DR   Pfam; PF18272; ssDNA_TraI_N; 1.
DR   Pfam; PF18340; TraI_2B; 1.
DR   Pfam; PF07057; TraI_C; 1.
DR   Pfam; PF22232; TraI_hel_assoc_N; 1.
DR   Pfam; PF08751; TrwC; 1.
DR   SUPFAM; SSF55464; Origin of replication-binding domain, RBD-like; 1.
DR   SUPFAM; SSF52540; P-loop containing nucleoside triphosphate hydrolases; 2.
PE   3: Inferred from homology;
KW   ATP-binding; Coiled coil; Conjugation; Cytoplasm; DNA-binding; Helicase;
KW   Hydrolase; Isomerase; Magnesium; Metal-binding; Mobility protein;
KW   Multifunctional enzyme; Nucleotide-binding; Plasmid.
FT   CHAIN           1..1756
FT                   /note="Multifunctional conjugation protein TraI"
FT                   /id="PRO_0000068453"
FT   REGION          1..330
FT                   /note="DNA relaxase"
FT   REGION          1..306
FT                   /note="DNA trans-esterase domain"
FT                   /evidence="ECO:0000250|UniProtKB:Q6TDU5"
FT   REGION          315..828
FT                   /note="Vestigal helicase domain"
FT                   /evidence="ECO:0000250|UniProtKB:Q6TDU5"
FT   REGION          864..1461
FT                   /note="Active helicase domain"
FT                   /evidence="ECO:0000250|UniProtKB:Q6TDU5"
FT   REGION          950..1500
FT                   /note="DNA helicase I"
FT   REGION          1462..1756
FT                   /note="C-terminal domain"
FT                   /evidence="ECO:0000250|UniProtKB:Q6TDU5"
FT   COILED          1719..1753
FT                   /evidence="ECO:0000255"
FT   ACT_SITE        16
FT                   /note="O-(5'-phospho-DNA)-tyrosine intermediate; for
FT                   relaxase activity"
FT                   /evidence="ECO:0000250|UniProtKB:P14565"
FT   ACT_SITE        17
FT                   /note="Relaxase"
FT                   /evidence="ECO:0000255"
FT   BINDING         146
FT                   /ligand="Mg(2+)"
FT                   /ligand_id="ChEBI:CHEBI:18420"
FT                   /ligand_note="catalytic"
FT                   /evidence="ECO:0000250|UniProtKB:P14565"
FT   BINDING         157
FT                   /ligand="Mg(2+)"
FT                   /ligand_id="ChEBI:CHEBI:18420"
FT                   /ligand_note="catalytic"
FT                   /evidence="ECO:0000250|UniProtKB:P14565"
FT   BINDING         159
FT                   /ligand="Mg(2+)"
FT                   /ligand_id="ChEBI:CHEBI:18420"
FT                   /ligand_note="catalytic"
FT                   /evidence="ECO:0000250|UniProtKB:P14565"
FT   BINDING         992..999
FT                   /ligand="ATP"
FT                   /ligand_id="ChEBI:CHEBI:30616"
FT                   /evidence="ECO:0000255"
SQ   SEQUENCE   1756 AA;  191681 MW;  B394B666141153F3 CRC64;
     MLSFSVVKSA GSAGNYYTDK DNYYVLGSMG ERWAGQGAEQ LGLQGSVDKD VFTRLLEGRL
     PDGADLSRMQ DGSNKHRPGY DLTFSAPKSV SMMAMLGGDK RLIDAHNQAV DFAVRQVEAL
     ASTRVMTDGQ SETVLTGNLV MALFNHDTSR DQDPQLHTHV VVANVTQHNG EWKTLSSDKV
     GKTGFSENVL ANRIAFGKIY QSELRQRVEA LGYETEVVGK HGMWEMPGVP VEAFSSRSQA
     IREAVGEDAS LKSRDVAALD TRKSKHHVDP EVRMAEWMQT LKETGFDIRA YRDAADQRAE
     IRTQAPGPAS QDGPDVQQAV TQAIAGLSER KVQFTYTDVL ARTVGILPPE NGVIERARAG
     IDEAISREQL IPLDREKGLF TSGIHVLDEL SVRALSRDIM KQNRVTVHPE KSVPRTAGYS
     DAVSVLAQDR PSLAIVSGQG GAAGQRERVA ELVMMAREQG REVQIIAADR RSQLNLKQDE
     RLSGELITGR RQLQEGMVFT SGSTFIVDQG EKLSLKETLT LLDGAARHNV QVLITDSGQR
     TGTGSALMAM KDAGVNTYRW QGGEQRPATI ISEPDRNVRY DRLAGDFAAS VKAGEESVAQ
     VSGVREQAIL TQAIRSELKT QGVLGHPEVT MTALSPVWLD SRSRYLRDMY RPGMVMEQWN
     PETRSHDRYV IDRVTAQSHS LTLRDAQGET QVVRISSLDS SWSLFRPEKM PVADGERLRV
     TGKIPGLRVS GGDRLQVASV SEDAMTVVVP GRAEPATLPV ADSPFTALKL ENGWVETPGH
     SVSDSATVFA SVTQMAMDNA TLNGLARSGR DVRLYSSLDE TRTAEKLARH PSFTVVSEQI
     KARAGETSLE TAISLQKTGL HTPAQQAIHL ALPVLESKNL AFSMVDLLTE AKSFAAEGTG
     FTELGGEINA QIKRGDLLYV DVAKGYGTGL LVSRASYEAE KSILRHILEG KEAVTPLMER
     VPGELMETLT SGPRAATRMI LETSDRFTVV QGYAGVGKTT QFRAVMSAVN MLPASERPRV
     VGLGPTHRAV GEMRSAGVDA QTLASFLHDT QLQQRSGETP DFSNTLFLLD ESSMVGNTDM
     ARAYALIAAG GGRAVASGDT DQLQAIAPGQ PFRLQQTRSA ADVVIMKEIV RQTPELREAV
     YSLINRDVER ALSGLESVKP SQVPRQEGAW APEHSVTEFS HSQEAKLAEA QQKAMLKGET
     FPDVPMTLYE AIVRDYTGRT PEAREQTLIV THLNEDRRVL NSMIHDAREK AGELGKEQVM
     VPVLNTANIR DGELRRLSTW ENNPDALALV DSVYHRIAGI SKDDGLITLE DAEGNTRLIS
     PREAVAEGVT LYTPDKIRVG TGDRMRFTKS DRERGYVANS VWTVTAVSGD SVTLSDGQQT
     RVIRPGQERA EQHIDLAYAI TAHGAQGASE TFAIALEGTE GNRKLMAGFE SAYVALSRMK
     QHVQVYTDNR QGWTDAINNA VQKGTAHDVL EPKPDREVMN AQRLFSTARE LRDVAAGRAV
     LRQAGLAGGD SPARFIAPGR KYPQPYVALP AFDRNGKSAG IWLNPLTTDD GNGLRGFSGE
     GRVKGSGDAQ FVALQGSRNG ESLLADNMQD GVRIARDNPD SGVVVRIAGE GRPWNPGAIT
     GGRVWGDIPD SSVQPGAGNG EPVTAEVLAQ RQAEEAIRRE TERRADEIVR KMAENKPDLP
     DGKTEQAVRE IAGQERDRAD ITEREAALPE SVLRESQREQ EAVREVAREN LLQERLQQIE
     RDMVRDLQKE KTLGGD
//