ID   DPO3B_MYCPN             Reviewed;         380 AA.
AC   Q50313;
DT   01-NOV-1997, integrated into UniProtKB/Swiss-Prot.
DT   01-NOV-1997, sequence version 1.
DT   03-AUG-2022, entry version 111.
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=MPN_001; ORFNames=MP153;
OS   Mycoplasma pneumoniae (strain ATCC 29342 / M129) (Mycoplasmoides
OS   pneumoniae).
OC   Bacteria; Tenericutes; Mollicutes; Mycoplasmataceae; Mycoplasma.
OX   NCBI_TaxID=272634;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [GENOMIC DNA].
RC   STRAIN=ATCC 29342 / M129;
RX   PubMed=8604303; DOI=10.1093/nar/24.4.628;
RA   Hilbert H., Himmelreich R., Plagens H., Herrmann R.;
RT   "Sequence analysis of 56 kb from the genome of the bacterium Mycoplasma
RT   pneumoniae comprising the dnaA region, the atp operon and a cluster of
RT   ribosomal protein genes.";
RL   Nucleic Acids Res. 24:628-639(1996).
RN   [2]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC   STRAIN=ATCC 29342 / M129;
RX   PubMed=8948633; DOI=10.1093/nar/24.22.4420;
RA   Himmelreich R., Hilbert H., Plagens H., Pirkl E., Li B.-C., Herrmann R.;
RT   "Complete sequence analysis of the genome of the bacterium Mycoplasma
RT   pneumoniae.";
RL   Nucleic Acids Res. 24:4420-4449(1996).
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; U34816; AAC43645.1; -; Genomic_DNA.
DR   EMBL; U00089; AAG34739.1; -; Genomic_DNA.
DR   PIR; S62836; S62836.
DR   RefSeq; NP_109689.1; NC_000912.1.
DR   RefSeq; WP_010874358.1; NC_000912.1.
DR   AlphaFoldDB; Q50313; -.
DR   SMR; Q50313; -.
DR   IntAct; Q50313; 1.
DR   STRING; 272634.MPN_001; -.
DR   EnsemblBacteria; AAG34739; AAG34739; MPN_001.
DR   KEGG; mpn:MPN_001; -.
DR   PATRIC; fig|272634.6.peg.1; -.
DR   HOGENOM; CLU_727268_0_0_14; -.
DR   OMA; CIKITAN; -.
DR   BioCyc; MPNE272634:G1GJ3-4-MON; -.
DR   Proteomes; UP000000808; 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   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..380
FT                   /note="Beta sliding clamp"
FT                   /id="PRO_0000105446"
SQ   SEQUENCE   380 AA;  43856 MW;  AE3F5717962D3DFB CRC64;
     MKVLINKNEL NKILKKLNNV IVSNNKMKPY HSYLLIEATE KEINFYANNE YFSAKCTLAE
     NIDVLEEGEV IVKGKIFSEL INGIKEDIIT IQEKDQTLLV KTKKTNINLN TIDKKEFPRI
     RFNQNVDLKE FDELKIQHSL LTKGLKKIAH AVSTFRESTR KFNGVNFNGS NGKQIFLEAS
     DSYKLSVYEI KQKTDPFNFI VETNLLSFIN SFNPEGGDLI SIFFRKEHKD DLSTELLIKL
     DNFLINYTSI NESFPRVMQL FDFEPETKVT IQKNELKDAL QRILTLAQNE RFFLCDMQVT
     NSHLKINSNV QNIGASLEEV TCLKFEGHKL NIAVNALSLL EHIDSFDTDE IELYFQGSNK
     YFLISSNNEP ELKEILVPSK