EX7L_ECOLI
ID EX7L_ECOLI Reviewed; 456 AA.
AC P04994; P78230;
DT 13-AUG-1987, integrated into UniProtKB/Swiss-Prot.
DT 01-NOV-1997, sequence version 2.
DT 03-AUG-2022, entry version 176.
DE RecName: Full=Exodeoxyribonuclease 7 large subunit {ECO:0000255|HAMAP-Rule:MF_00378};
DE EC=3.1.11.6 {ECO:0000255|HAMAP-Rule:MF_00378, ECO:0000269|PubMed:4602029, ECO:0000269|PubMed:4602030};
DE AltName: Full=Exodeoxyribonuclease VII large subunit {ECO:0000255|HAMAP-Rule:MF_00378, ECO:0000303|PubMed:4602029};
DE Short=ExoVII large subunit;
DE Short=Exonuclease VII large subunit {ECO:0000255|HAMAP-Rule:MF_00378, ECO:0000303|PubMed:3021756};
GN Name=xseA {ECO:0000255|HAMAP-Rule:MF_00378, ECO:0000303|PubMed:3021756};
GN OrderedLocusNames=b2509, JW2493;
OS Escherichia coli (strain K12).
OC Bacteria; Proteobacteria; Gammaproteobacteria; Enterobacterales;
OC Enterobacteriaceae; Escherichia.
OX NCBI_TaxID=83333;
RN [1]
RP NUCLEOTIDE SEQUENCE [GENOMIC DNA], AND PROTEIN SEQUENCE OF 1-12; 21-34;
RP 70-82; 224-242; 303-311; 371-375; 386-399 AND 425-431.
RC STRAIN=K12;
RX PubMed=3021756; DOI=10.1016/s0021-9258(18)66806-1;
RA Chase J.W., Rabin B.A., Murphy J.B., Stone K.L., Williams K.R.;
RT "Escherichia coli exonuclease VII. Cloning and sequencing of the gene
RT encoding the large subunit (xseA).";
RL J. Biol. Chem. 261:14929-14935(1986).
RN [2]
RP NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC STRAIN=K12 / W3110 / ATCC 27325 / DSM 5911;
RX PubMed=9205837; DOI=10.1093/dnares/4.2.91;
RA Yamamoto Y., Aiba H., Baba T., Hayashi K., Inada T., Isono K., Itoh T.,
RA Kimura S., Kitagawa M., Makino K., Miki T., Mitsuhashi N., Mizobuchi K.,
RA Mori H., Nakade S., Nakamura Y., Nashimoto H., Oshima T., Oyama S.,
RA Saito N., Sampei G., Satoh Y., Sivasundaram S., Tagami H., Takahashi H.,
RA Takeda J., Takemoto K., Uehara K., Wada C., Yamagata S., Horiuchi T.;
RT "Construction of a contiguous 874-kb sequence of the Escherichia coli-K12
RT genome corresponding to 50.0-68.8 min on the linkage map and analysis of
RT its sequence features.";
RL DNA Res. 4:91-113(1997).
RN [3]
RP NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC STRAIN=K12 / MG1655 / ATCC 47076;
RX PubMed=9278503; DOI=10.1126/science.277.5331.1453;
RA Blattner F.R., Plunkett G. III, Bloch C.A., Perna N.T., Burland V.,
RA Riley M., Collado-Vides J., Glasner J.D., Rode C.K., Mayhew G.F.,
RA Gregor J., Davis N.W., Kirkpatrick H.A., Goeden M.A., Rose D.J., Mau B.,
RA Shao Y.;
RT "The complete genome sequence of Escherichia coli K-12.";
RL Science 277:1453-1462(1997).
RN [4]
RP NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC STRAIN=K12 / W3110 / ATCC 27325 / DSM 5911;
RX PubMed=16738553; DOI=10.1038/msb4100049;
RA Hayashi K., Morooka N., Yamamoto Y., Fujita K., Isono K., Choi S.,
RA Ohtsubo E., Baba T., Wanner B.L., Mori H., Horiuchi T.;
RT "Highly accurate genome sequences of Escherichia coli K-12 strains MG1655
RT and W3110.";
RL Mol. Syst. Biol. 2:E1-E5(2006).
RN [5]
RP CATALYTIC ACTIVITY, NO COFACTOR, AND BIOPHYSICOCHEMICAL PROPERTIES.
RC STRAIN=K12;
RX PubMed=4602029; DOI=10.1016/s0021-9258(19)42453-8;
RA Chase J.W., Richardson C.C.;
RT "Exonuclease VII of Escherichia coli. Purification and properties.";
RL J. Biol. Chem. 249:4545-4552(1974).
RN [6]
RP CATALYTIC ACTIVITY.
RC STRAIN=K12;
RX PubMed=4602030; DOI=10.1016/s0021-9258(19)42454-x;
RA Chase J.W., Richardson C.C.;
RT "Exonuclease VII of Escherichia coli. Mechanism of action.";
RL J. Biol. Chem. 249:4553-4561(1974).
RN [7]
RP FUNCTION, SUBUNIT, AND SUBCELLULAR LOCATION.
RC STRAIN=K12;
RX PubMed=6284744; DOI=10.1016/s0021-9258(18)34201-7;
RA Vales L.D., Rabin B.A., Chase J.W.;
RT "Subunit structure of Escherichia coli exonuclease VII.";
RL J. Biol. Chem. 257:8799-8805(1982).
RN [8]
RP FUNCTION, CATALYTIC ACTIVITY, SUBUNIT, DOMAIN, SSDNA-BINDING, AND
RP MUTAGENESIS OF PHE-63; 64-ARG--ARG-69; GLN-96; ASP-155; GLN-177; ARG-205;
RP HIS-238; ASP-241; ASP-246; ASP-250; THR-255 AND 397-SER--HIS-456.
RX PubMed=22718974; DOI=10.1093/nar/gks547;
RA Poleszak K., Kaminska K.H., Dunin-Horkawicz S., Lupas A., Skowronek K.J.,
RA Bujnicki J.M.;
RT "Delineation of structural domains and identification of functionally
RT important residues in DNA repair enzyme exonuclease VII.";
RL Nucleic Acids Res. 40:8163-8174(2012).
RN [9]
RP FUNCTION IN MSDNA PROCESSING, DOMAIN, DISRUPTION PHENOTYPE, AND MUTAGENESIS
RP OF ASP-155; ALA-188 AND GLY-237.
RC STRAIN=K12 / BW25113;
RX PubMed=26626352; DOI=10.1007/s12275-015-5304-0;
RA Jung H., Liang J., Jung Y., Lim D.;
RT "Characterization of cell death in Escherichia coli mediated by XseA, a
RT large subunit of exonuclease VII.";
RL J. Microbiol. 53:820-828(2015).
CC -!- FUNCTION: Bidirectionally degrades single-stranded DNA into large acid-
CC insoluble oligonucleotides, which are then degraded further into small
CC acid-soluble oligonucleotides. It can degrade 3' or 5' ss regions
CC extending from the termini of duplex DNA molecules and displaced ss
CC regions. It can also excise thymine dimers in vitro (PubMed:4602029,
CC PubMed:4602030, PubMed:22718974) (Probable). ssDNA-binding requires
CC both subunits (PubMed:22718974). Required for production of the mature
CC 5'-end of retron Ec78 or Ec83 msDNA. Overproduction of this subunit in
CC the absence of an equivalent quantity of the small subunit is toxic,
CC causing cell elongation and chromosome fragmentation or loss; its
CC toxicity is mostly suppressed by RecA (PubMed:26626352).
CC {ECO:0000269|PubMed:22718974, ECO:0000269|PubMed:26626352,
CC ECO:0000269|PubMed:4602029, ECO:0000269|PubMed:4602030,
CC ECO:0000305|PubMed:6284744}.
CC -!- CATALYTIC ACTIVITY:
CC Reaction=Exonucleolytic cleavage in either 5'- to 3'- or 3'- to 5'-
CC direction to yield nucleoside 5'-phosphates.; EC=3.1.11.6;
CC Evidence={ECO:0000255|HAMAP-Rule:MF_00378,
CC ECO:0000269|PubMed:22718974, ECO:0000269|PubMed:4602029,
CC ECO:0000269|PubMed:4602030};
CC -!- COFACTOR:
CC Note=Does not require a metal cofactor. {ECO:0000269|PubMed:4602029};
CC -!- BIOPHYSICOCHEMICAL PROPERTIES:
CC pH dependence:
CC Optimum pH is 7.8 to 7.9. {ECO:0000269|PubMed:4602029};
CC -!- SUBUNIT: Heterooligomer composed of two different subunits with an
CC approximate ratio of 4:1 for small to large subunit (Probable). Also
CC estimated to have a 6:1 ration for small to large subunits (Probable).
CC {ECO:0000305|PubMed:22718974, ECO:0000305|PubMed:6284744}.
CC -!- INTERACTION:
CC P04994; P76168: intQ; NbExp=3; IntAct=EBI-559703, EBI-559711;
CC -!- SUBCELLULAR LOCATION: Cytoplasm {ECO:0000305|PubMed:6284744}.
CC -!- DOMAIN: Predicted to have 4 domains. The N-terminus (about residues 1-
CC 103) binds ssDNA and is required to bind the small subunit; it probably
CC has an OB-fold. The predicted catalytic domain is residues 104-266.
CC Three alpha-helices are predicted in the C-terminal region (residues
CC 267-301, 307-349 and 353-393), their removal singly or in pairs reduces
CC small subunit-binding; none of the deletions have exonuclease activity.
CC The extreme C-terminus (394-456) is required for exonuclease activity
CC (PubMed:22718974). The N-terminus (residues 1-257) at low levels does
CC not confer processing of msDNA and at higher levels is lethal.
CC Lethality of this fragment is not counteracted by the small subunit
CC (PubMed:26626352). {ECO:0000269|PubMed:22718974,
CC ECO:0000269|PubMed:26626352}.
CC -!- DISRUPTION PHENOTYPE: No longer processes msDNA correctly (when retron
CC Ec78 or Ec83 are expressed in the strain).
CC {ECO:0000269|PubMed:26626352}.
CC -!- SIMILARITY: Belongs to the XseA family. {ECO:0000255|HAMAP-
CC Rule:MF_00378}.
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DR EMBL; J02599; AAA24766.1; -; Genomic_DNA.
DR EMBL; U00096; AAC75562.1; -; Genomic_DNA.
DR EMBL; AP009048; BAA16396.1; -; Genomic_DNA.
DR PIR; D65027; NCEC7.
DR RefSeq; NP_417004.1; NC_000913.3.
DR RefSeq; WP_000937912.1; NZ_LN832404.1.
DR AlphaFoldDB; P04994; -.
DR BioGRID; 4263222; 85.
DR BioGRID; 851327; 1.
DR ComplexPortal; CPX-4005; Exodeoxyribonuclease VII complex.
DR DIP; DIP-11146N; -.
DR IntAct; P04994; 9.
DR STRING; 511145.b2509; -.
DR jPOST; P04994; -.
DR PaxDb; P04994; -.
DR PRIDE; P04994; -.
DR DNASU; 946988; -.
DR EnsemblBacteria; AAC75562; AAC75562; b2509.
DR EnsemblBacteria; BAA16396; BAA16396; BAA16396.
DR GeneID; 946988; -.
DR KEGG; ecj:JW2493; -.
DR KEGG; eco:b2509; -.
DR PATRIC; fig|1411691.4.peg.4227; -.
DR EchoBASE; EB1065; -.
DR eggNOG; COG1570; Bacteria.
DR HOGENOM; CLU_023625_3_1_6; -.
DR InParanoid; P04994; -.
DR OMA; WPAVRFE; -.
DR PhylomeDB; P04994; -.
DR BioCyc; EcoCyc:EG11072-MON; -.
DR BioCyc; MetaCyc:EG11072-MON; -.
DR BRENDA; 3.1.11.6; 2026.
DR PRO; PR:P04994; -.
DR Proteomes; UP000000318; Chromosome.
DR Proteomes; UP000000625; Chromosome.
DR GO; GO:0005737; C:cytoplasm; IEA:UniProtKB-SubCell.
DR GO; GO:0009318; C:exodeoxyribonuclease VII complex; IPI:ComplexPortal.
DR GO; GO:0008855; F:exodeoxyribonuclease VII activity; IEA:UniProtKB-UniRule.
DR GO; GO:0003676; F:nucleic acid binding; IEA:InterPro.
DR GO; GO:0000738; P:DNA catabolic process, exonucleolytic; IDA:ComplexPortal.
DR GO; GO:0006298; P:mismatch repair; IDA:ComplexPortal.
DR CDD; cd04489; ExoVII_LU_OBF; 1.
DR HAMAP; MF_00378; Exonuc_7_L; 1.
DR InterPro; IPR003753; Exonuc_VII_L.
DR InterPro; IPR020579; Exonuc_VII_lsu_C.
DR InterPro; IPR025824; OB-fold_nuc-bd_dom.
DR PANTHER; PTHR30008; PTHR30008; 1.
DR Pfam; PF02601; Exonuc_VII_L; 1.
DR Pfam; PF13742; tRNA_anti_2; 1.
DR TIGRFAMs; TIGR00237; xseA; 1.
PE 1: Evidence at protein level;
KW Cytoplasm; Direct protein sequencing; DNA-binding; Exonuclease; Hydrolase;
KW Nuclease; Reference proteome.
FT CHAIN 1..456
FT /note="Exodeoxyribonuclease 7 large subunit"
FT /id="PRO_0000197845"
FT REGION 1..103
FT /note="Binds ssDNA, also required to bind the small
FT subunit"
FT /evidence="ECO:0000269|PubMed:22718974"
FT MUTAGEN 63
FT /note="F->A: About 10% ssDNA-binding by N-terminal domain."
FT /evidence="ECO:0000269|PubMed:22718974"
FT MUTAGEN 64..69
FT /note="RNSNRR->ENSNEE: About 20% ssDNA-binding by N-
FT terminal domain."
FT /evidence="ECO:0000269|PubMed:22718974"
FT MUTAGEN 96
FT /note="Q->A: About 50% ssDNA-binding by N-terminal domain."
FT /evidence="ECO:0000269|PubMed:22718974"
FT MUTAGEN 155
FT /note="D->A: Loss of exonuclease activity, reduced ssDNA-
FT binding."
FT /evidence="ECO:0000269|PubMed:22718974"
FT MUTAGEN 155
FT /note="D->N: Does not cleave Ec83 msDNA, not lethal on
FT overexpression."
FT /evidence="ECO:0000269|PubMed:26626352"
FT MUTAGEN 177
FT /note="Q->A: Wild-type exonuclease activity."
FT /evidence="ECO:0000269|PubMed:22718974"
FT MUTAGEN 188
FT /note="A->T: Cleaves EC83 msDNA normally, reduced toxicity
FT on overexpression."
FT /evidence="ECO:0000269|PubMed:26626352"
FT MUTAGEN 205
FT /note="R->A: Loss of exonuclease activity, still binds
FT ssDNA."
FT /evidence="ECO:0000269|PubMed:22718974"
FT MUTAGEN 237
FT /note="G->R: Does not cleave Ec83 msDNA, 10-fold reduced
FT toxicity on overexpression."
FT /evidence="ECO:0000269|PubMed:26626352"
FT MUTAGEN 238
FT /note="H->A: Loss of exonuclease activity, still binds
FT ssDNA."
FT /evidence="ECO:0000269|PubMed:22718974"
FT MUTAGEN 241
FT /note="D->A: Loss of exonuclease activity, still binds
FT ssDNA."
FT /evidence="ECO:0000269|PubMed:22718974"
FT MUTAGEN 246
FT /note="D->A: Wild-type exonuclease activity."
FT /evidence="ECO:0000269|PubMed:22718974"
FT MUTAGEN 250
FT /note="D->A: Wild-type exonuclease activity."
FT /evidence="ECO:0000269|PubMed:22718974"
FT MUTAGEN 255
FT /note="T->A: Wild-type exonuclease activity."
FT /evidence="ECO:0000269|PubMed:22718974"
FT MUTAGEN 397..456
FT /note="Missing: Loss of exonuclease activity."
FT /evidence="ECO:0000269|PubMed:22718974"
FT CONFLICT 67
FT /note="N -> S (in Ref. 1; AAA24766)"
FT /evidence="ECO:0000305"
SQ SEQUENCE 456 AA; 51832 MW; A5E5B138C54A7D27 CRC64;
MLPSQSPAIF TVSRLNQTVR LLLEHEMGQV WISGEISNFT QPASGHWYFT LKDDTAQVRC
AMFRNSNRRV TFRPQHGQQV LVRANITLYE PRGDYQIIVE SMQPAGEGLL QQKYEQLKAK
LQAEGLFDQQ YKKPLPSPAH CVGVITSKTG AALHDILHVL KRRDPSLPVI IYPAAVQGDD
APGQIVRAIE LANQRNECDV LIVGRGGGSL EDLWSFNDER VARAIFTSRI PVVSAVGHET
DVTIADFVAD LRAPTPSAAA EVVSRNQQEL LRQVQSTRQR LEMAMDYYLA NRTRRFTQIH
HRLQQQHPQL RLARQQTMLE RLQKRMSFAL ENQLKRTGQQ QQRLTQRLNQ QNPQPKIHRA
QTRIQQLEYR LAETLRAQLS ATRERFGNAV THLEAVSPLS TLARGYSVTT ATDGNVLKKV
KQVKAGEMLT TRLEDGWIES EVKNIQPVKK SRKKVH
