ID   DPO3B_SERMA             Reviewed;          78 AA.
AC   P29438;
DT   01-APR-1993, integrated into UniProtKB/Swiss-Prot.
DT   01-FEB-1996, sequence version 2.
DT   25-MAY-2022, entry version 69.
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;
DE   Flags: Fragment;
GN   Name=dnaN;
OS   Serratia marcescens.
OC   Bacteria; Proteobacteria; Gammaproteobacteria; Enterobacterales;
OC   Yersiniaceae; Serratia.
OX   NCBI_TaxID=615;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [GENOMIC DNA].
RX   PubMed=3040670; DOI=10.1128/jb.169.9.3976-3981.1987;
RA   Skovgaard O., Hansen F.G.;
RT   "Comparison of dnaA nucleotide sequences of Escherichia coli, Salmonella
RT   typhimurium, and Serratia marcescens.";
RL   J. Bacteriol. 169:3976-3981(1987).
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; M17353; AAA02925.1; -; Genomic_DNA.
DR   AlphaFoldDB; P29438; -.
DR   SMR; P29438; -.
DR   STRING; 273526.SMDB11_4152; -.
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   InterPro; IPR001001; DNA_polIII_beta.
DR   InterPro; IPR022634; DNA_polIII_beta_N.
DR   PANTHER; PTHR30478; PTHR30478; 1.
DR   Pfam; PF00712; DNA_pol3_beta; 1.
PE   3: Inferred from homology;
KW   Cytoplasm; DNA replication; DNA-binding; DNA-directed DNA polymerase;
KW   Nucleotidyltransferase; Transferase.
FT   CHAIN           1..>78
FT                   /note="Beta sliding clamp"
FT                   /id="PRO_0000105460"
FT   NON_TER         78
SQ   SEQUENCE   78 AA;  8548 MW;  A4BB281DB3A04BF9 CRC64;
     MKFIVEREHL LKPLQQVSSP LGGRPTLPIL GNLLLQVTEG SLLLTGTDLE MEMVARVALS
     QPHEPGATTV PARKFFDI