>TIGR01054 rgy reverse gyrase; InterPro: IPR005736 DNA topoisomerases regulate the number of topological links between two DNA strands (i.e. change the number of superhelical turns) by catalysing transient single- or double-strand breaks, crossing the strands through one another, then resealing the breaks. These enzymes have several functions: to remove DNA supercoils during transcription and DNA replication; for strand breakage during recombination; for chromosome condensation; and to disentangle intertwined DNA during mitosis , . DNA topoisomerases are divided into two classes: type I enzymes (5.99.1.2 from EC; topoisomerases I, III and V) break single-strand DNA, and type II enzymes (5.99.1.3 from EC; topoisomerases II, IV and VI) break double-strand DNA . Type I topoisomerases are ATP-independent enzymes (except for reverse gyrase), and can be subdivided according to their structure and reaction mechanisms: type IA (bacterial and archaeal topoisomerase I, topoisomerase III and reverse gyrase) and type IB (eukaryotic topoisomerase I and topoisomerase V). These enzymes are primarily responsible for relaxing positively and/or negatively supercoiled DNA, except for reverse gyrase, which can introduce positive supercoils into DNA. Reverse gyrase is a type IA topoisomerase that is unique among these enzymes in its requirement for ATP. Reverse gyrase is a hyperthermophile-specific enzyme that acts as a renaturase by positively supercoiling DNA, and by annealing complementary single-strand circles . Hyperthermophilic organisms must protect themselves against heat-induced degradation, and reverse gyrase acts to reduce the rate of double-strand DNA breakage, a function that does not require ATP hydrolysis and which is independent of its positive supercoiling abilities. Reverse gyrase achieves this by recognising nicked DNA and recruiting a protein coat to the site of damage . More information about this protein can be found at Protein of the Month: DNA Topoisomerase .; GO: 0003677 DNA binding, 0003916 DNA topoisomerase activity, 0006265 DNA topological change, 0006268 DNA unwinding during replication, 0005694 chromosome.

Probab=96.85 E-value=0.015 Score=34.62 Aligned_cols=200 Identities=18% Similarity=0.101 Sum_probs=104.7 Q ss_pred EEEECCCCCCHHHHHHHHHHHHHHHCCCCEEEEECCCHHHHHHHHHHHHHHHHHHCCCCCCCCCC--CCCCCCCCCCCCC Q ss_conf 77614886788999999999999708997799971537999999999999999862312112333--3210001233322 Q gi|254781187|r 80 CAISAGRGIGKTTLNAWMMLWLISTRPGMSIICIANSETQLKNTLWAEVSKWLSMLPHRHWFEMQ--SLSLHPSGWYAEL 157 (367) Q Consensus 80 ~~v~sgrg~GKS~~~a~~~lw~~~~~~~~~v~~~A~t~~Q~~~~lw~ei~k~~~~~~~~~~~~~~--~~~~~~~~~~~~~ 157 (367) T Consensus 102 Fai~APTGVGKttFG~~mslflA~k-KGkR~y~ilPT~lLv~Qv~-~kl~~~~~k~g----~~~~~l~~~yhS~L~~~~k 175 (1843) T TIGR01054 102 FAIVAPTGVGKTTFGLVMSLFLAKK-KGKRSYIILPTTLLVKQVA-EKLSSLAEKEG----VGIVRLLGAYHSKLSTKEK 175 (1843) T ss_pred EEEECCCCCCHHHHHHHHHHHHHHH-CCCEEEEEECHHHHHHHHH-HHHHHHCCCCC----CCCEEEEEEEECCCCHHHH T ss_conf 4898058876779999999998654-2987899947078899999-99875200257----5000022210112654567 Q ss_pred CCCCCCCCCCCEEEEECCCCCCCCCCCCCCC-CCCCCEEEEECCCCC----------------CH----HHHHHH----- Q ss_conf 1111345776126621013544556521011-358628999754559----------------98----899998----- Q gi|254781187|r 158 LEQSMGIDSKHYTITCRTYSEERPDTFVGPH-NTHGMAVFNDEASGT----------------PD----IINKSI----- 211 (367) Q Consensus 158 ~~~~~~~~~~~~~~~a~~~~~~~~ea~~g~h-~~~~~l~ivDEAsgI----------------~d----~i~e~i----- 211 (367) T Consensus 176 ke~~Eri~~GDfdilitT-~~FL~K~~~~L~~~y~F~liFVDDVDa~Lk~skNVD~~L~LlGF~eE~i~~a~~~i~L~~k 254 (1843) T TIGR01054 176 KEVKERIENGDFDILITT-SMFLSKNFDKLKNQYKFDLIFVDDVDALLKASKNVDKILKLLGFSEELIEKAYELIKLKLK 254 (1843) T ss_pred HHHHHHHHCCCEEEEHHH-HHHHHHHHHHCCCCCEEEEEEEECHHHHHHCCCCHHHHHHHHCCCHHHHHHHHHHHHHHHH T ss_conf 889998731891786122-4688876651789851448997153676316555667775517889999999999999887 Q ss_pred ---------------------------------HHHHHCCCCCEEEEEEECCC-CCCCHHHHHHHCCC-------CCE-E Q ss_conf ---------------------------------98740698825899980789-99876887541122-------350-4 Q gi|254781187|r 212 ---------------------------------LGFFTELNPNRFWIMTSNTR-RLNGWFYDIFNIPL-------EDW-K 249 (367) Q Consensus 212 ---------------------------------~g~Lt~~~~~~~~i~igNP~-r~~g~Fye~~~~~~-------~~w-~ 249 (367) T Consensus 255 ~~k~~~~~~~~~~~~R~E~~~~~LE~~~r~~~~~a~~~~krGr~g~LivsSATG~prG~r~~LFR~LL~FevG~~~~~GL 334 (1843) T TIGR01054 255 ENKLEEDLAREKIVVRLEARKKLLEAKRRLEKLEAEIKKKRGRKGVLIVSSATGKPRGKRVKLFRELLGFEVGKGSDTGL 334 (1843) T ss_pred HHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHCCCCCEEEEEEECCCCCCCCHHHHHHHHCCCCCCCCCCCCC T ss_conf 64357788888886467888999999999898776474324886469998514888761336536552710057642233 Q ss_pred EEEECCCCCCCC-CHHHHHH---HHHHCCCCCCEEEEEEEE Q ss_conf 675233328888-9889999---996216880002688864 Q gi|254781187|r 250 RYQIDTRTVEGI-DSGFHEG---IISRYGLDSDVARIEILG 286 (367) Q Consensus 250 ~~~~~~~d~p~~-~~~~i~~---~~~~~gedS~~~r~ev~G 286 (367) T Consensus 335 RnvvD~y~~~~d~v~E~~~~sve~v~~LG~GGlVyvs~~yG 375 (1843) T TIGR01054 335 RNVVDVYEEDEDGVKEKLLESVELVKKLGKGGLVYVSIDYG 375 (1843) T ss_pred CCEEEEEECCCCCHHHHHHHHHHHHHHHCCCEEEEEECCCC T ss_conf 21388511488844688999999999847943999712225

HHsearch alignment for GI: 254781187 and conserved domain: TIGR01054