ID   GYRB_RHOCA              Reviewed;         134 AA.
AC   P31860;
DT   01-JUL-1993, integrated into UniProtKB/Swiss-Prot.
DT   01-JUL-1993, sequence version 1.
DT   25-MAY-2022, entry version 84.
DE   RecName: Full=DNA gyrase subunit B;
DE            EC=5.6.2.2 {ECO:0000250|UniProtKB:P0AES6};
DE   Flags: Fragment;
GN   Name=gyrB;
OS   Rhodobacter capsulatus (Rhodopseudomonas capsulata).
OC   Bacteria; Proteobacteria; Alphaproteobacteria; Rhodobacterales;
OC   Rhodobacteraceae; Rhodobacter.
OX   NCBI_TaxID=1061;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [GENOMIC DNA].
RX   PubMed=1319375; DOI=10.1016/0378-1097(92)90484-6;
RA   Kranz R.G., Beckman D.L., Foster-Hartnett D.;
RT   "DNA gyrase activities from Rhodobacter capsulatus: analysis of target(s)
RT   of coumarins and cloning of the gyrB locus.";
RL   FEMS Microbiol. Lett. 72:25-32(1992).
CC   -!- FUNCTION: A type II topoisomerase that negatively supercoils closed
CC       circular double-stranded (ds) DNA in an ATP-dependent manner to
CC       modulate DNA topology and maintain chromosomes in an underwound state.
CC       Negative supercoiling favors strand separation, and DNA replication,
CC       transcription, recombination and repair, all of which involve strand
CC       separation. Also able to catalyze the interconversion of other
CC       topological isomers of dsDNA rings, including catenanes and knotted
CC       rings. Type II topoisomerases break and join 2 DNA strands
CC       simultaneously in an ATP-dependent manner.
CC       {ECO:0000250|UniProtKB:P0AES6}.
CC   -!- CATALYTIC ACTIVITY:
CC       Reaction=ATP-dependent breakage, passage and rejoining of double-
CC         stranded DNA.; EC=5.6.2.2; Evidence={ECO:0000250|UniProtKB:P0AES6};
CC   -!- SUBUNIT: Heterotetramer, composed of two GyrA and two GyrB chains. In
CC       the heterotetramer, GyrA contains the active site tyrosine that forms a
CC       transient covalent intermediate with DNA, while GyrB binds cofactors
CC       and catalyzes ATP hydrolysis. {ECO:0000250|UniProtKB:P0AES6}.
CC   -!- SUBCELLULAR LOCATION: Cytoplasm {ECO:0000250|UniProtKB:P0AES6}.
CC   -!- MISCELLANEOUS: Few gyrases are as efficient as E.coli at forming
CC       negative supercoils. Not all organisms have 2 type II topoisomerases;
CC       in organisms with a single type II topoisomerase this enzyme also has
CC       to decatenate newly replicated chromosomes.
CC       {ECO:0000250|UniProtKB:P0AES6}.
CC   -!- SIMILARITY: Belongs to the type II topoisomerase GyrB family.
CC       {ECO:0000305}.
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DR   AlphaFoldDB; P31860; -.
DR   SMR; P31860; -.
DR   GO; GO:0005737; C:cytoplasm; IEA:UniProtKB-SubCell.
DR   GO; GO:0005524; F:ATP binding; IEA:UniProtKB-KW.
DR   GO; GO:0003677; F:DNA binding; IEA:InterPro.
DR   GO; GO:0003918; F:DNA topoisomerase type II (double strand cut, ATP-hydrolyzing) activity; IEA:UniProtKB-EC.
DR   GO; GO:0006265; P:DNA topological change; IEA:InterPro.
DR   Gene3D; 3.30.230.10; -; 1.
DR   InterPro; IPR020568; Ribosomal_S5_D2-typ_fold.
DR   InterPro; IPR014721; Ribosomal_S5_D2-typ_fold_subgr.
DR   InterPro; IPR013506; Topo_IIA_bsu_dom2.
DR   Pfam; PF00204; DNA_gyraseB; 1.
DR   SUPFAM; SSF54211; SSF54211; 1.
PE   3: Inferred from homology;
KW   ATP-binding; Cytoplasm; Isomerase; Nucleotide-binding; Topoisomerase.
FT   CHAIN           <1..>134
FT                   /note="DNA gyrase subunit B"
FT                   /id="PRO_0000145330"
FT   NON_TER         1
FT   NON_TER         134
SQ   SEQUENCE   134 AA;  14961 MW;  24176BFBFEF28C83 CRC64;
     EFVKYLDRSK TAVMPDPIYM VGEVRGIGVE VAMWWNDSYH ETVLPFTNNI PQRDGGTHLA
     GFRGALTRTI TKYAQDSGIA KREKIDFTGD DAREGLTCVL SVKVPDPKFS SQTKDKLVSS
     EVRPAVENLV NEKL