ID   DPO3B_STRR6             Reviewed;         378 AA.
AC   P59651;
DT   30-APR-2003, integrated into UniProtKB/Swiss-Prot.
DT   30-APR-2003, sequence version 1.
DT   25-MAY-2022, entry version 100.
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=spr0002;
OS   Streptococcus pneumoniae (strain ATCC BAA-255 / R6).
OC   Bacteria; Firmicutes; Bacilli; Lactobacillales; Streptococcaceae;
OC   Streptococcus.
OX   NCBI_TaxID=171101;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC   STRAIN=ATCC BAA-255 / R6;
RX   PubMed=11544234; DOI=10.1128/jb.183.19.5709-5717.2001;
RA   Hoskins J., Alborn W.E. Jr., Arnold J., Blaszczak L.C., Burgett S.,
RA   DeHoff B.S., Estrem S.T., Fritz L., Fu D.-J., Fuller W., Geringer C.,
RA   Gilmour R., Glass J.S., Khoja H., Kraft A.R., Lagace R.E., LeBlanc D.J.,
RA   Lee L.N., Lefkowitz E.J., Lu J., Matsushima P., McAhren S.M., McHenney M.,
RA   McLeaster K., Mundy C.W., Nicas T.I., Norris F.H., O'Gara M., Peery R.B.,
RA   Robertson G.T., Rockey P., Sun P.-M., Winkler M.E., Yang Y.,
RA   Young-Bellido M., Zhao G., Zook C.A., Baltz R.H., Jaskunas S.R.,
RA   Rosteck P.R. Jr., Skatrud P.L., Glass J.I.;
RT   "Genome of the bacterium Streptococcus pneumoniae strain R6.";
RL   J. Bacteriol. 183:5709-5717(2001).
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; AE007317; AAK98806.1; -; Genomic_DNA.
DR   RefSeq; NP_357596.1; NC_003098.1.
DR   RefSeq; WP_000581138.1; NC_003098.1.
DR   AlphaFoldDB; P59651; -.
DR   SMR; P59651; -.
DR   STRING; 171101.spr0002; -.
DR   EnsemblBacteria; AAK98806; AAK98806; spr0002.
DR   GeneID; 60232672; -.
DR   KEGG; spr:spr0002; -.
DR   PATRIC; fig|171101.6.peg.2; -.
DR   eggNOG; COG0592; Bacteria.
DR   HOGENOM; CLU_038149_2_0_9; -.
DR   OMA; YLIMPVR; -.
DR   Proteomes; UP000000586; 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:0006271; P:DNA strand elongation involved in DNA replication; IBA:GO_Central.
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..378
FT                   /note="Beta sliding clamp"
FT                   /id="PRO_0000105473"
SQ   SEQUENCE   378 AA;  42071 MW;  14CE29278184F906 CRC64;
     MIHFSINKNL FLQALNITKR AISSKNAIPI LSTVKIDVTN EGVTLIGSNG QISIENFISQ
     KNEDAGLLIT SLGSILLEAS FFINVVSSLP DVTLDFKEIE QNQIVLTSGK SEITLKGKDS
     EQYPRIQEIS ASTPLILETK LLKKIINETA FAASTQESRP ILTGVHFVLS QHKELKTVAT
     DSHRLSQKKL TLEKNSDDFD VVIPSRSLRE FSAVFTDDIE TVEIFFANNQ ILFRSENISF
     YTRLLEGNYP DTDRLIPTDF NTTITFNVVN LRQSMERARL LSSATQNGTV KLEIKDGVVS
     AHVHSPEVGK VNEEIDTDQV TGEDLTISFN PTYLIDSLKA LNSEKVTISF ISAVRPFTLV
     PADTDEDFMQ LITPVRTN