ID   DPO3B_MYCGE             Reviewed;         380 AA.
AC   P47247;
DT   01-FEB-1996, integrated into UniProtKB/Swiss-Prot.
DT   20-DEC-2017, sequence version 3.
DT   02-SEP-2026, entry version 137.
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=MG001;
OS   Mycoplasmoides genitalium (strain ATCC 33530 / DSM 19775 / NCTC 10195 /
OS   G37) (Mycoplasma genitalium).
OC   Bacteria; Bacillati; Mycoplasmatota; Mycoplasmoidales; Mycoplasmoidaceae;
OC   Mycoplasmoides.
OX   NCBI_TaxID=243273;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC   STRAIN=ATCC 33530 / DSM 19775 / NCTC 10195 / G37;
RX   PubMed=7569993; DOI=10.1126/science.270.5235.397;
RA   Fraser C.M., Gocayne J.D., White O., Adams M.D., Clayton R.A.,
RA   Fleischmann R.D., Bult C.J., Kerlavage A.R., Sutton G.G., Kelley J.M.,
RA   Fritchman J.L., Weidman J.F., Small K.V., Sandusky M., Fuhrmann J.L.,
RA   Nguyen D.T., Utterback T.R., Saudek D.M., Phillips C.A., Merrick J.M.,
RA   Tomb J.-F., Dougherty B.A., Bott K.F., Hu P.-C., Lucier T.S.,
RA   Peterson S.N., Smith H.O., Hutchison C.A. III, Venter J.C.;
RT   "The minimal gene complement of Mycoplasma genitalium.";
RL   Science 270:397-403(1995).
RN   [2]
RP   SEQUENCE REVISION.
RA   Fraser C.M., Gocayne J.D., White O., Adams M.D., Clayton R.A.,
RA   Fleischmann R.D., Bult C.J., Kerlavage A.R., Sutton G.G., Kelley J.M.,
RA   Fritchman J.L., Weidman J.F., Small K.V., Sandusky M., Fuhrmann J.L.,
RA   Nguyen D.T., Utterback T.R., Saudek D.M., Phillips C.A., Merrick J.M.,
RA   Tomb J.-F., Dougherty B.A., Bott K.F., Hu P.-C., Lucier T.S.,
RA   Peterson S.N., Smith H.O., Hutchison C.A. III, Venter J.C.;
RL   Submitted (OCT-1998) to the EMBL/GenBank/DDBJ databases.
RN   [3]
RP   NUCLEOTIDE SEQUENCE [GENOMIC DNA] OF 283-380.
RC   STRAIN=ATCC 33530 / DSM 19775 / NCTC 10195 / G37;
RX   PubMed=8083173; DOI=10.1128/jb.176.18.5814-5819.1994;
RA   Bailey C.C., Bott K.F.;
RT   "An unusual gene containing a dnaJ N-terminal box flanks the putative
RT   origin of replication of Mycoplasma genitalium.";
RL   J. Bacteriol. 176:5814-5819(1994).
RN   [4]
RP   SEQUENCE REVISION, AND DISRUPTION PHENOTYPE.
RC   STRAIN=ATCC 33530 / DSM 19775 / NCTC 10195 / G37;
RX   PubMed=16407165; DOI=10.1073/pnas.0510013103;
RA   Glass J.I., Assad-Garcia N., Alperovich N., Yooseph S., Lewis M.R.,
RA   Maruf M., Hutchison C.A. III, Smith H.O., Venter J.C.;
RT   "Essential genes of a minimal bacterium.";
RL   Proc. Natl. Acad. Sci. U.S.A. 103:425-430(2006).
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   -!- DISRUPTION PHENOTYPE: Probably essential, it was not disrupted in a
CC       global transposon mutagenesis study. {ECO:0000269|PubMed:16407165}.
CC   -!- SIMILARITY: Belongs to the beta sliding clamp family. {ECO:0000305}.
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DR   EMBL; L43967; AAC71217.2; -; Genomic_DNA.
DR   EMBL; U09251; AAA57069.1; -; Genomic_DNA.
DR   RefSeq; WP_009885562.1; NC_000908.2.
DR   AlphaFoldDB; P47247; -.
DR   SMR; P47247; -.
DR   FunCoup; P47247; 149.
DR   STRING; 243273.MG_001; -.
DR   GeneID; 99646809; -.
DR   KEGG; mge:MG_001; -.
DR   eggNOG; COG0592; Bacteria.
DR   HOGENOM; CLU_727268_0_0_14; -.
DR   InParanoid; P47247; -.
DR   OrthoDB; 397417at2; -.
DR   BioCyc; MGEN243273:G1GJ2-1-MONOMER; -.
DR   Proteomes; UP000000807; Chromosome.
DR   GO; GO:0005737; C:cytoplasm; ISS:UniProtKB.
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:InterPro.
DR   GO; GO:0003887; F:DNA-directed DNA polymerase activity; IEA:InterPro.
DR   GO; GO:0006271; P:DNA strand elongation involved in DNA replication; IBA:GO_Central.
DR   CDD; cd00140; beta_clamp; 1.
DR   Gene3D; 3.70.10.10; -; 1.
DR   Gene3D; 3.10.150.10; DNA Polymerase III, subunit A, domain 2; 1.
DR   InterPro; IPR046938; DNA_clamp_sf.
DR   InterPro; IPR001001; DNA_polIII_beta.
DR   InterPro; IPR022635; DNA_polIII_beta_C.
DR   InterPro; IPR022634; DNA_polIII_beta_N.
DR   NCBIfam; TIGR00663; dnan; 1.
DR   PANTHER; PTHR30478:SF0; BETA SLIDING CLAMP; 1.
DR   PANTHER; PTHR30478; DNA POLYMERASE III SUBUNIT BETA; 1.
DR   Pfam; PF00712; DNA_pol3_beta; 1.
DR   Pfam; PF02768; DNA_pol3_beta_3; 1.
DR   SMART; SM00480; POL3Bc; 1.
DR   SUPFAM; SSF55979; DNA clamp; 3.
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_0000105445"
SQ   SEQUENCE   380 AA;  44295 MW;  5FAB2B23550FC563 CRC64;
     MKILINKSEL NKILKKMNNV IISNNKIKPH HSYFLIEAKE KEINFYANNE YFSVKCNLNK
     NIDILEQGSL IVKGKIFNDL INGIKEEIIT IQEKDQTLLV KTKKTSINLN TINVNEFPRI
     RFNEKNDLSE FNQFKINYSL LVKGIKKIFH SVSNNREISS KFNGVNFNGS NGKEIFLEAS
     DTYKLSVFEI KQETEPFDFI LESNLLSFIN SFNPEEDKSI VFYYRKDNKD SFSTEMLISM
     DNFMISYTSV NEKFPEVNYF FEFEPETKIV VQKNELKDAL QRIQTLAQNE RTFLCDMQIN
     SSELKIRAIV NNIGNSLEEI SCLKFEGYKL NISFNPSSLL DHIESFESNE INFDFQGNSK
     YFLITSKSEP ELKQILVPSR
//