ID   DPO3B_STRCO             Reviewed;         376 AA.
AC   P27903;
DT   01-AUG-1992, integrated into UniProtKB/Swiss-Prot.
DT   01-AUG-1992, sequence version 1.
DT   25-MAY-2022, entry version 119.
DE   RecName: Full=Beta sliding clamp;
DE            Short=Beta clamp;
DE            Short=Sliding clamp;
DE   AltName: Full=Beta-clamp processivity factor;
DE   AltName: Full=DNA polymerase III beta sliding clamp subunit;
DE   AltName: Full=DNA polymerase III subunit beta;
GN   Name=dnaN; OrderedLocusNames=SCO3878; ORFNames=SCH18.15c;
OS   Streptomyces coelicolor (strain ATCC BAA-471 / A3(2) / M145).
OC   Bacteria; Actinobacteria; Streptomycetales; Streptomycetaceae;
OC   Streptomyces; Streptomyces albidoflavus group.
OX   NCBI_TaxID=100226;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [GENOMIC DNA].
RC   STRAIN=A3(2) / NRRL B-16638;
RX   PubMed=1577691; DOI=10.1128/jb.174.10.3220-3226.1992;
RA   Calcutt M.J., Schmidt F.J.;
RT   "Conserved gene arrangement in the origin region of the Streptomyces
RT   coelicolor chromosome.";
RL   J. Bacteriol. 174:3220-3226(1992).
RN   [2]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC   STRAIN=ATCC BAA-471 / A3(2) / M145;
RX   PubMed=12000953; DOI=10.1038/417141a;
RA   Bentley S.D., Chater K.F., Cerdeno-Tarraga A.-M., Challis G.L.,
RA   Thomson N.R., James K.D., Harris D.E., Quail M.A., Kieser H., Harper D.,
RA   Bateman A., Brown S., Chandra G., Chen C.W., Collins M., Cronin A.,
RA   Fraser A., Goble A., Hidalgo J., Hornsby T., Howarth S., Huang C.-H.,
RA   Kieser T., Larke L., Murphy L.D., Oliver K., O'Neil S., Rabbinowitsch E.,
RA   Rajandream M.A., Rutherford K.M., Rutter S., Seeger K., Saunders D.,
RA   Sharp S., Squares R., Squares S., Taylor K., Warren T., Wietzorrek A.,
RA   Woodward J.R., Barrell B.G., Parkhill J., Hopwood D.A.;
RT   "Complete genome sequence of the model actinomycete Streptomyces coelicolor
RT   A3(2).";
RL   Nature 417:141-147(2002).
CC   -!- FUNCTION: Confers DNA tethering and processivity to DNA polymerases and
CC       other proteins. Acts as a clamp, forming a ring around DNA (a reaction
CC       catalyzed by the clamp-loading complex) which diffuses in an ATP-
CC       independent manner freely and bidirectionally along dsDNA. Initially
CC       characterized for its ability to contact the catalytic subunit of DNA
CC       polymerase III (Pol III), a complex, multichain enzyme responsible for
CC       most of the replicative synthesis in bacteria; Pol III exhibits 3'-5'
CC       exonuclease proofreading activity. The beta chain is required for
CC       initiation of replication as well as for processivity of DNA
CC       replication. {ECO:0000250|UniProtKB:P0A988}.
CC   -!- SUBUNIT: Forms a ring-shaped head-to-tail homodimer around DNA which
CC       binds and tethers DNA polymerases and other proteins to the DNA. The
CC       DNA replisome complex has a single clamp-loading complex (3 tau and 1
CC       each of delta, delta', psi and chi subunits) which binds 3 Pol III
CC       cores (1 core on the leading strand and 2 on the lagging strand) each
CC       with a beta sliding clamp dimer. Additional proteins in the replisome
CC       are other copies of gamma, psi and chi, Ssb, DNA helicase and RNA
CC       primase. {ECO:0000250|UniProtKB:P0A988}.
CC   -!- SUBCELLULAR LOCATION: Cytoplasm {ECO:0000250|UniProtKB:P0A988}.
CC   -!- SIMILARITY: Belongs to the beta sliding clamp family. {ECO:0000305}.
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DR   EMBL; AF187159; AAA26735.1; -; Genomic_DNA.
DR   EMBL; AL939118; CAB92998.1; -; Genomic_DNA.
DR   PIR; B41870; B41870.
DR   RefSeq; NP_628065.1; NC_003888.3.
DR   RefSeq; WP_003975054.1; NZ_VNID01000003.1.
DR   AlphaFoldDB; P27903; -.
DR   SMR; P27903; -.
DR   STRING; 100226.SCO3878; -.
DR   GeneID; 1099314; -.
DR   KEGG; sco:SCO3878; -.
DR   PATRIC; fig|100226.15.peg.3951; -.
DR   eggNOG; COG0592; Bacteria.
DR   HOGENOM; CLU_038149_1_1_11; -.
DR   InParanoid; P27903; -.
DR   OMA; YLIMPVR; -.
DR   PhylomeDB; P27903; -.
DR   Proteomes; UP000001973; Chromosome.
DR   GO; GO:0005737; C:cytoplasm; IEA:UniProtKB-SubCell.
DR   GO; GO:0009360; C:DNA polymerase III complex; IEA:InterPro.
DR   GO; GO:0008408; F:3'-5' exonuclease activity; IEA:InterPro.
DR   GO; GO:0003677; F:DNA binding; IEA:UniProtKB-KW.
DR   GO; GO:0003887; F:DNA-directed DNA polymerase activity; IEA:UniProtKB-KW.
DR   GO; GO:0006260; P:DNA replication; IEA:UniProtKB-KW.
DR   CDD; cd00140; beta_clamp; 1.
DR   InterPro; IPR001001; DNA_polIII_beta.
DR   InterPro; IPR022635; DNA_polIII_beta_C.
DR   InterPro; IPR022637; DNA_polIII_beta_cen.
DR   InterPro; IPR022634; DNA_polIII_beta_N.
DR   PANTHER; PTHR30478; PTHR30478; 1.
DR   Pfam; PF00712; DNA_pol3_beta; 1.
DR   Pfam; PF02767; DNA_pol3_beta_2; 1.
DR   Pfam; PF02768; DNA_pol3_beta_3; 1.
DR   PIRSF; PIRSF000804; DNA_pol_III_b; 1.
DR   SMART; SM00480; POL3Bc; 1.
DR   TIGRFAMs; TIGR00663; dnan; 1.
PE   3: Inferred from homology;
KW   Cytoplasm; DNA replication; DNA-binding; DNA-directed DNA polymerase;
KW   Nucleotidyltransferase; Reference proteome; Transferase.
FT   CHAIN           1..376
FT                   /note="Beta sliding clamp"
FT                   /id="PRO_0000105471"
SQ   SEQUENCE   376 AA;  39956 MW;  F11C285D703EF567 CRC64;
     MKIRVERDVL AEAVAWAARS LPARPPAPVL AGLLLKAEEG QLSLSSFDYE VSARVSVEAE
     IEEEGTVLVS GRLLADISRA LPNRPVEIST DGVRATVVCG SSRFTLHTLP VEEYPALPQM
     PEATGTVPGE VFASAVQQVA IAAGRDDTLP VLTGVRIEIE GDSVTLASTD RYRFAVREFL
     WKPENPDISA VALVPAKTLQ DTAKALTSGD QVILALSGSG AGEGLIGFEG AGRRTTTRLL
     EGDLPKYKTL FPTEFNSVAV IETAPFVEAV KRVALVAERN TPVRLSFEQG VLILEAGSSD
     DAQAVERVDA QLEGDDISIA FNPTFLLDGL SAIDSPVAQL SFTTSTKPAL LSGRPAVDAE
     ADEAYKYLIM PVRLSG