>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=96.91  E-value=0.0034  Score=44.62  Aligned_cols=95  Identities=21%  Similarity=0.238  Sum_probs=69.0

Q ss_pred             EEEECCCCCCHHHHHHHHHHHHHHHCCCCEE-EECCCCCCCHHHHHHHHHHHCCCCCC---CCCCCCCHHHHHHHHHHHH
Q ss_conf             9962344333468899999999861489507-82054221004779999851034742---2233210368999999999
Q gi|254780711|r  103 IMLVGLQGSGKTTTTAKIAYHLKTLKKKKIL-MASLDVHRPAAQEQLRYLGEQIQVDT---LEVIPEQSPEKIAIRATQS  178 (461)
Q Consensus       103 IllvGl~GsGKTTT~aKLA~~~~~~~~~kV~-lv~~Dt~R~aA~eQL~~~a~~~~v~~---~~~~~~~dp~~i~~~a~~~  178 (461)
T Consensus       102 Fai~APTGVGKttFG~~mslflA~kKGkR~y~ilPT~lLv~Qv~~kl~~~~~k~g~~~~~l~~~yhS~L~~~~kke~~Er  181 (1843)
T TIGR01054       102 FAIVAPTGVGKTTFGLVMSLFLAKKKGKRSYIILPTTLLVKQVAEKLSSLAEKEGVGIVRLLGAYHSKLSTKEKKEVKER  181 (1843)
T ss_pred             EEEECCCCCCHHHHHHHHHHHHHHHCCCEEEEEECHHHHHHHHHHHHHHHCCCCCCCCEEEEEEEECCCCHHHHHHHHHH
T ss_conf             48980588767799999999986542987899947078899999998752002575000022210112654567889998


Q ss_pred             HHHCCCCEEEEECCCCCCCH
Q ss_conf             97415886998334422211
Q gi|254780711|r  179 ARDGGYDAVILDTAGRNHIN  198 (461)
Q Consensus       179 a~~~~~D~iiiDTaGR~~~d  198 (461)
T Consensus       182 i~~GDfd-ilitT~~FL~K~  200 (1843)
T TIGR01054       182 IENGDFD-ILITTSMFLSKN  200 (1843)
T ss_pred             HHCCCEE-EEHHHHHHHHHH
T ss_conf             7318917-861224688876