ID   GYRBP_ARATH             Reviewed;         730 AA.
AC   Q9SS38; F4J2L8;
DT   25-JUL-2006, integrated into UniProtKB/Swiss-Prot.
DT   22-FEB-2012, sequence version 3.
DT   02-SEP-2026, entry version 148.
DE   RecName: Full=DNA gyrase subunit B, chloroplastic {ECO:0000303|PubMed:15136745};
DE            Short=AtGyrB1 {ECO:0000303|PubMed:20360860};
DE            Short=AtcpgyrB {ECO:0000303|PubMed:15136745};
DE            EC=5.6.2.2 {ECO:0000255|PROSITE-ProRule:PRU00995};
DE   Flags: Precursor;
GN   Name=GYRBC {ECO:0000303|PubMed:15136745};
GN   Synonyms=GYRB1 {ECO:0000303|PubMed:20360860};
GN   OrderedLocusNames=At3g10270 {ECO:0000312|Araport:AT3G10270};
GN   ORFNames=F14P13.13 {ECO:0000312|EMBL:AAF02815.1};
OS   Arabidopsis thaliana (Mouse-ear cress).
OC   Eukaryota; Viridiplantae; Streptophyta; Embryophyta; Tracheophyta;
OC   Spermatophyta; Magnoliopsida; eudicotyledons; Gunneridae; Pentapetalae;
OC   rosids; malvids; Brassicales; Brassicaceae; Camelineae; Arabidopsis.
OX   NCBI_TaxID=3702;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC   STRAIN=cv. Columbia;
RX   PubMed=11130713; DOI=10.1038/35048706;
RA   Salanoubat M., Lemcke K., Rieger M., Ansorge W., Unseld M., Fartmann B.,
RA   Valle G., Bloecker H., Perez-Alonso M., Obermaier B., Delseny M.,
RA   Boutry M., Grivell L.A., Mache R., Puigdomenech P., De Simone V.,
RA   Choisne N., Artiguenave F., Robert C., Brottier P., Wincker P.,
RA   Cattolico L., Weissenbach J., Saurin W., Quetier F., Schaefer M.,
RA   Mueller-Auer S., Gabel C., Fuchs M., Benes V., Wurmbach E., Drzonek H.,
RA   Erfle H., Jordan N., Bangert S., Wiedelmann R., Kranz H., Voss H.,
RA   Holland R., Brandt P., Nyakatura G., Vezzi A., D'Angelo M., Pallavicini A.,
RA   Toppo S., Simionati B., Conrad A., Hornischer K., Kauer G., Loehnert T.-H.,
RA   Nordsiek G., Reichelt J., Scharfe M., Schoen O., Bargues M., Terol J.,
RA   Climent J., Navarro P., Collado C., Perez-Perez A., Ottenwaelder B.,
RA   Duchemin D., Cooke R., Laudie M., Berger-Llauro C., Purnelle B., Masuy D.,
RA   de Haan M., Maarse A.C., Alcaraz J.-P., Cottet A., Casacuberta E.,
RA   Monfort A., Argiriou A., Flores M., Liguori R., Vitale D., Mannhaupt G.,
RA   Haase D., Schoof H., Rudd S., Zaccaria P., Mewes H.-W., Mayer K.F.X.,
RA   Kaul S., Town C.D., Koo H.L., Tallon L.J., Jenkins J., Rooney T., Rizzo M.,
RA   Walts A., Utterback T., Fujii C.Y., Shea T.P., Creasy T.H., Haas B.,
RA   Maiti R., Wu D., Peterson J., Van Aken S., Pai G., Militscher J.,
RA   Sellers P., Gill J.E., Feldblyum T.V., Preuss D., Lin X., Nierman W.C.,
RA   Salzberg S.L., White O., Venter J.C., Fraser C.M., Kaneko T., Nakamura Y.,
RA   Sato S., Kato T., Asamizu E., Sasamoto S., Kimura T., Idesawa K.,
RA   Kawashima K., Kishida Y., Kiyokawa C., Kohara M., Matsumoto M., Matsuno A.,
RA   Muraki A., Nakayama S., Nakazaki N., Shinpo S., Takeuchi C., Wada T.,
RA   Watanabe A., Yamada M., Yasuda M., Tabata S.;
RT   "Sequence and analysis of chromosome 3 of the plant Arabidopsis thaliana.";
RL   Nature 408:820-822(2000).
RN   [2]
RP   GENOME REANNOTATION.
RC   STRAIN=cv. Columbia;
RX   PubMed=27862469; DOI=10.1111/tpj.13415;
RA   Cheng C.Y., Krishnakumar V., Chan A.P., Thibaud-Nissen F., Schobel S.,
RA   Town C.D.;
RT   "Araport11: a complete reannotation of the Arabidopsis thaliana reference
RT   genome.";
RL   Plant J. 89:789-804(2017).
RN   [3]
RP   GENOME REANNOTATION.
RC   STRAIN=cv. Columbia;
RG   The Arabidopsis Information Resource (TAIR);
RT   "Community-consensus reference genome of Arabidopsis thaliana Col-0.";
RL   Submitted (FEB-2026) to the EMBL/GenBank/DDBJ databases.
RN   [4]
RP   FUNCTION, SUBCELLULAR LOCATION, GENE FAMILY, AND NOMENCLATURE.
RC   STRAIN=cv. Columbia, and cv. Landsberg erecta;
RX   PubMed=15136745; DOI=10.1073/pnas.0400836101;
RA   Wall M.K., Mitchenall L.A., Maxwell A.;
RT   "Arabidopsis thaliana DNA gyrase is targeted to chloroplasts and
RT   mitochondria.";
RL   Proc. Natl. Acad. Sci. U.S.A. 101:7821-7826(2004).
RN   [5]
RP   TISSUE SPECIFICITY.
RX   PubMed=20360860; DOI=10.1371/journal.pone.0009899;
RA   Evans-Roberts K.M., Breuer C., Wall M.K., Sugimoto-Shirasu K., Maxwell A.;
RT   "Arabidopsis thaliana GYRB3 does not encode a DNA gyrase subunit.";
RL   PLoS ONE 5:e9899-e9899(2010).
CC   -!- FUNCTION: A type II topoisomerase that negatively supercoils closed
CC       circular double-stranded DNA in an ATP-dependent manner.
CC       {ECO:0000269|PubMed:15136745}.
CC   -!- CATALYTIC ACTIVITY:
CC       Reaction=ATP-dependent breakage, passage and rejoining of double-
CC         stranded DNA.; EC=5.6.2.2; Evidence={ECO:0000255|PROSITE-
CC         ProRule:PRU00995};
CC   -!- COFACTOR:
CC       Name=Mg(2+); Xref=ChEBI:CHEBI:18420; Evidence={ECO:0000255|PROSITE-
CC         ProRule:PRU00995};
CC       Name=Mn(2+); Xref=ChEBI:CHEBI:29035; Evidence={ECO:0000255|PROSITE-
CC         ProRule:PRU00995};
CC       Name=Ca(2+); Xref=ChEBI:CHEBI:29108; Evidence={ECO:0000255|PROSITE-
CC         ProRule:PRU00995};
CC       Note=Binds two Mg(2+) per subunit. The magnesium ions form salt bridges
CC       with both the protein and the DNA. Can also accept other divalent metal
CC       cations, such as Mn(2+) or Ca(2+). {ECO:0000255|PROSITE-
CC       ProRule:PRU00995};
CC   -!- SUBUNIT: Made up of two chains. The A chain is responsible for DNA
CC       breakage and rejoining; the B chain catalyzes ATP hydrolysis.
CC       {ECO:0000250|UniProtKB:P0AES6}.
CC   -!- SUBCELLULAR LOCATION: Plastid, chloroplast
CC       {ECO:0000269|PubMed:15136745}.
CC   -!- TISSUE SPECIFICITY: Mainly expressed in seeds and shoot apex, to a
CC       lower extent in leaves, seedlings, roots, stems, flowers and carpels
CC       and, at low levels, in stamens and pollen.
CC       {ECO:0000269|PubMed:20360860}.
CC   -!- SIMILARITY: Belongs to the type II topoisomerase GyrB family.
CC       {ECO:0000305}.
CC   -!- SEQUENCE CAUTION:
CC       Sequence=AAF02815.1; Type=Erroneous gene model prediction; Evidence={ECO:0000305};
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DR   EMBL; AC009400; AAF02815.1; ALT_SEQ; Genomic_DNA.
DR   EMBL; CP002686; AEE74882.2; -; Genomic_DNA.
DR   EMBL; OZ408685; -; NOT_ANNOTATED_CDS; Genomic_DNA.
DR   AlphaFoldDB; Q9SS38; -.
DR   SMR; Q9SS38; -.
DR   BioGRID; 5523; 1.
DR   FunCoup; Q9SS38; 530.
DR   STRING; 3702.Q9SS38; -.
DR   PaxDb; 3702-Q9SS38; -.
DR   ProteomicsDB; 247328; -.
DR   KEGG; ath:AT3G10270; -.
DR   Araport; AT3G10270; -.
DR   TAIR; AT3G10270; GYRB1.
DR   eggNOG; KOG0355; Eukaryota.
DR   InParanoid; Q9SS38; -.
DR   CD-CODE; 4299E36E; Nucleolus.
DR   PRO; PR:Q9SS38; -.
DR   Proteomes; UP000006548; Chromosome 3.
DR   ExpressionAtlas; Q9SS38; baseline and differential.
DR   GO; GO:0009507; C:chloroplast; IDA:TAIR.
DR   GO; GO:0042644; C:chloroplast nucleoid; HDA:TAIR.
DR   GO; GO:0005694; C:chromosome; IEA:InterPro.
DR   GO; GO:0005737; C:cytoplasm; IDA:TAIR.
DR   GO; GO:0009330; C:DNA topoisomerase type II (double strand cut, ATP-hydrolyzing) complex; IBA:GO_Central.
DR   GO; GO:0005739; C:mitochondrion; IDA:TAIR.
DR   GO; GO:0005524; F:ATP binding; IEA:InterPro.
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; IBA:GO_Central.
DR   CDD; cd16928; HATPase_GyrB-like; 1.
DR   CDD; cd00822; TopoII_Trans_DNA_gyrase; 1.
DR   CDD; cd03366; TOPRIM_TopoIIA_GyrB; 1.
DR   FunFam; 3.30.230.10:FF:000005; DNA gyrase subunit B; 1.
DR   FunFam; 3.30.565.10:FF:000002; DNA gyrase subunit B; 1.
DR   FunFam; 3.40.50.670:FF:000002; DNA gyrase subunit B; 1.
DR   Gene3D; 3.30.230.10; -; 1.
DR   Gene3D; 3.40.50.670; -; 1.
DR   Gene3D; 3.30.565.10; Histidine kinase-like ATPase, C-terminal domain; 1.
DR   InterPro; IPR002288; DNA_gyrase_B_C.
DR   InterPro; IPR011557; GyrB.
DR   InterPro; IPR036890; HATPase_C_sf.
DR   InterPro; IPR003594; HATPase_dom.
DR   InterPro; IPR020568; Ribosomal_Su5_D2-typ_SF.
DR   InterPro; IPR014721; Ribsml_uS5_D2-typ_fold_subgr.
DR   InterPro; IPR001241; Topo_IIA.
DR   InterPro; IPR013760; Topo_IIA-like_dom_sf.
DR   InterPro; IPR000565; Topo_IIA_B.
DR   InterPro; IPR013759; Topo_IIA_B_C.
DR   InterPro; IPR013506; Topo_IIA_bsu_dom2.
DR   InterPro; IPR018522; TopoIIA_CS.
DR   InterPro; IPR006171; TOPRIM_dom.
DR   InterPro; IPR034160; TOPRIM_GyrB.
DR   NCBIfam; TIGR01059; gyrB; 1.
DR   NCBIfam; NF004189; PRK05644.1; 1.
DR   PANTHER; PTHR45866:SF7; DNA GYRASE SUBUNIT B, CHLOROPLASTIC; 1.
DR   PANTHER; PTHR45866; DNA GYRASE/TOPOISOMERASE SUBUNIT B; 1.
DR   Pfam; PF00204; DNA_gyraseB; 1.
DR   Pfam; PF00986; DNA_gyraseB_C; 1.
DR   Pfam; PF02518; HATPase_c; 1.
DR   Pfam; PF01751; Toprim; 1.
DR   PRINTS; PR01159; DNAGYRASEB.
DR   PRINTS; PR00418; TPI2FAMILY.
DR   SMART; SM00387; HATPase_c; 1.
DR   SMART; SM00433; TOP2c; 1.
DR   SUPFAM; SSF55874; ATPase domain of HSP90 chaperone/DNA topoisomerase II/histidine kinase; 1.
DR   SUPFAM; SSF54211; Ribosomal protein S5 domain 2-like; 1.
DR   SUPFAM; SSF56719; Type II DNA topoisomerase; 1.
DR   PROSITE; PS00177; TOPOISOMERASE_II; 1.
DR   PROSITE; PS50880; TOPRIM; 1.
PE   2: Evidence at transcript level;
KW   ATP-binding; Chloroplast; DNA-binding; Isomerase; Magnesium; Metal-binding;
KW   Nucleotide-binding; Plastid; Reference proteome; Topoisomerase;
KW   Transit peptide.
FT   TRANSIT         1..34
FT                   /note="Chloroplast"
FT                   /evidence="ECO:0000255"
FT   CHAIN           35..730
FT                   /note="DNA gyrase subunit B, chloroplastic"
FT                   /id="PRO_0000247948"
FT   DOMAIN          511..618
FT                   /note="Toprim"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU00995"
FT   BINDING         517
FT                   /ligand="Mg(2+)"
FT                   /ligand_id="ChEBI:CHEBI:18420"
FT                   /ligand_label="1"
FT                   /ligand_note="catalytic"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU00995"
FT   BINDING         591
FT                   /ligand="Mg(2+)"
FT                   /ligand_id="ChEBI:CHEBI:18420"
FT                   /ligand_label="1"
FT                   /ligand_note="catalytic"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU00995"
FT   BINDING         591
FT                   /ligand="Mg(2+)"
FT                   /ligand_id="ChEBI:CHEBI:18420"
FT                   /ligand_label="2"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU00995"
FT   BINDING         593
FT                   /ligand="Mg(2+)"
FT                   /ligand_id="ChEBI:CHEBI:18420"
FT                   /ligand_label="2"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU00995"
FT   SITE            542
FT                   /note="Interaction with DNA"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU00995"
FT   SITE            545
FT                   /note="Interaction with DNA"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU00995"
SQ   SEQUENCE   730 AA;  81048 MW;  69B8F1295071C4B5 CRC64;
     MALVQRQHSY LLRYFRLMAS RPRPRLFSHS LYPSLHRHSS ALSSSTPRIK FQLANVFSQR
     LVQRNAVSPK SFMSSTMESL QESSTSKDYS SEHIQVLEGL DPVRKRPGMY IGSTGSRGLH
     HLVYEILDNA IDEAQAGFAS KIDVVLHSDD SVSISDNGRG IPTDLHPATG KSSLETVLTV
     LHAGGKFGGK SSGYSVSGGL HGVGLSVVNA LSEALEVIVR RDGMEFQQKY SRGKPVTTLT
     CHVLPPESRG TQGTCIRFWP DKEVFTTAIQ FDHNTIAGRI RELAFLNPKV TISLKKEDDD
     PERDVYSEYF YAGGLTEYVS WLNTDKKPLH DVLGFRKEIN GSTVDVSLQW CSDAYSDTML
     GYANSIRTID GGTHIEGVKA SLTRTLNSLA KKLKVIKEKD ISLSGEHVRE GLTCIVSVKV
     PNPEFEGQTK TRLGNPEVRK IVDQSVQEYL TEYLELHPDV LESIISKSLN AYKAALAAKR
     ARELVRSKSV LKSSSLPGKL ADCSSTDPAE SEIFIVEGDS AGGSAKQGRD RRFQAILPLR
     GKILNIERKD EAAMYKNEEI QNLILGLGLG VKGEDFNKEN LRYHKIIILT DADVDGAHIR
     TLLLTFFFRY QRALFDAGCI YVGVPPLFKV ERGKQAHYCY DDAALKKITA SFPGNASYNI
     QRFKGLGEMM PAQLWETTMN PDTRILKQLV VDDAAETNMV FSSLMGARVD VRKELIKSAA
     TRMNLENLDI
//