Protein: DNA gyrase subunit B (EC 5.6.2.2) (Type IIA topoisomerase subunit GyrB) (P0AES6)
Organism: Escherichia coli (strain K12)
Function: DNA gyrase negatively supercoils closed circular double-stranded DNA in an ATP-dependent manner to maintain chromosomes in an underwound state. This makes better substrates for topoisomerase 4 (ParC and ParE) which is the main enzyme that unlinks newly replicated chromosomes in E.coli. Gyrase catalyzes the interconversion of other topological isomers of double-stranded DNA rings, including catenanes. Relaxes negatively supercoiled DNA in an ATP-independent manner. E.coli gyrase has higher supercoiling activity than other characterized bacterial gyrases; at comparable concentrations E.coli gyrase introduces more supercoils faster than M.tuberculosis gyrase, while M.tuberculosis gyrase has higher decatenation than supercoiling activity compared to E.coli. E.coli makes 15% more negative supercoils in pBR322 plasmid DNA than S.typhimurium; the S.typhimurium GyrB subunit is toxic in E.coli, while the E.coli copy can be expressed in S.typhimurium even though the 2 subunits have 777/804 residues identical. The enzymatic differences between E.coli gyrase and topoisomerase IV are largely due to the GyrA C-terminal domain (approximately residues 524-841) and specifically the GyrA-box.
Subcellular location: Cytoplasm {ECO:0000255|HAMAP-Rule:MF_01898}.
InterPro domains:
- IPR036890: Histidine kinase/HSP90-like ATPase superfamily (homologous_superfamily) [1-220]
- IPR002288: DNA gyrase B subunit, C-terminal (domain) [732-793]
- IPR011557: DNA gyrase, subunit B (family) [3-804]
- IPR000565: DNA topoisomerase, type IIA, subunit B (family) [5-789]
- IPR014721: Small ribosomal subunit protein uS5 domain 2-type fold, subgroup (homologous_superfamily) [221-390]
- IPR013760: DNA topoisomerase, type IIA-like domain superfamily (homologous_superfamily) [394-795]
- IPR041423: DNA gyrase subunit B insert domain (domain) [564-729]
- IPR049353: DNA gyrase subunit B, hook (domain) [533-561]
- IPR003594: Histidine kinase/HSP90-like ATPase domain (domain) [31-175]
- IPR018522: DNA topoisomerase, type IIA, conserved site (conserved_site) [422-430]
- IPR013759: DNA topoisomerase, type IIA, subunit B, C-terminal (homologous_superfamily) [391-803]
- IPR013506: DNA topoisomerase, type IIA, subunit B, domain 2 (domain) [221-390]
- IPR034160: DNA gyrase subunit B, TOPRIM domain (domain) [418-532]
- IPR020568: Ribosomal protein uS5 domain 2-type superfamily (homologous_superfamily) [221-392]
- IPR006171: TOPRIM domain (domain) [418-533]
- IPR001241: DNA topoisomerase, type IIA (family) [35-797]
Sequence:
MSNSYDSSSIKVLKGLDAVRKRPGMYIGDTDDGTGLHHMVFEVVDNAIDEALAGHCKEIIVTIHADNSVSVQDDGRGIPTGIHPEEGVSAAEVIMTVLHAGGKFDDNSYKVSGGLHGVGVSVVNALSQKLELVIQREGKIHRQIYEHGVPQAPLAVTGETEKTGTMVRFWPSLETFTNVTEFEYEILAKRLRELSFLNSGVSIRLRDKRDGKEDHFHYEGGIKAFVEYLNKNKTPIHPNIFYFSTEKDGIGVEVALQWNDGFQENIYCFTNNIPQRDGGTHLAGFRAAMTRTLNAYMDKEGYSKKAKVSATGDDAREGLIAVVSVKVPDPKFSSQTKDKLVSSEVKSAVEQQMNELLAEYLLENPTDAKIVVGKIIDAARAREAARRAREMTRRKGALDLAGLPGKLADCQERDPALSELYLVEGDSAGGSAKQGRNRKNQAILPLKGKILNVEKARFDKMLSSQEVATLITALGCGIGRDEYNPDKLRYHSIIIMTDADVDGSHIRTLLLTFFYRQMPEIVERGHVYIAQPPLYKVKKGKQEQYIKDDEAMDQYQISIALDGATLHTNASAPALAGEALEKLVSEYNATQKMINRMERRYPKAMLKELIYQPTLTEADLSDEQTVTRWVNALVSELNDKEQHGSQWKFDVHTNAEQNLFEPIVRVRTHGVDTDYPLDHEFITGGEYRRICTLGEKLRGLLEEDAFIERGERRQPVASFEQALDWLVKESRRGLSIQRYKGLGEMNPEQLWETTMDPESRRMLRVTVKDAIAADQLFTTLMGDAVEPRRAFIEENALKAANIDI
Predicted GO terms:
Molecular Function (MF): GO:0003674 (molecular function), GO:0005488 (binding), GO:0003824 (catalytic activity), GO:0140657 (ATP-dependent activity), GO:0016853 (isomerase activity), GO:0140640 (catalytic activity, acting on a nucleic acid), GO:0008094 (ATP-dependent activity, acting on DNA), GO:0005515 (protein binding), GO:0003916 (DNA topoisomerase activity), GO:0140097 (catalytic activity, acting on DNA), GO:0003918 (DNA topoisomerase type II (double strand cut, ATP-hydrolyzing) activity)
Biological Process (BP): GO:0008150 (biological process), GO:0009987 (cellular process), GO:0006276 (plasmid maintenance), GO:0071840 (cellular component organization or biogenesis), GO:0022402 (cell cycle process), GO:0007049 (cell cycle), GO:0016043 (cellular component organization), GO:0007062 (sister chromatid cohesion), GO:0006996 (organelle organization), GO:0051276 (chromosome organization)
Cellular Component (CC): GO:0005575 (cellular component), GO:0110165 (cellular anatomical entity), GO:0005737 (cytoplasm), GO:0005829 (cytosol), GO:0005622 (intracellular anatomical structure)