>TIGR01058 parE_Gpos DNA topoisomerase IV, B subunit; InterPro: IPR005740 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 II topoisomerases are ATP-dependent enzymes, and can be subdivided according to their structure and reaction mechanisms: type IIA (topoisomerase II or gyrase, and topoisomerase IV) and type IIB (topoisomerase VI). These enzymes are responsible for relaxing supercoiled DNA as well as for introducing both negative and positive supercoils . This entry represents subunit B (parE) of topoisomerase IV from Gram positive bacteria. Topoisomerase IV primarily decatenates DNA and relaxes positive supercoils, which is important in bacteria, where the circular chromosome becomes catenated, or linked, during replication . Topoisomerase IV consists of two polypeptide subunits, parC (subunit A), which is homologous to gyrA of topoisomerase II, and parE (subunit B), which is homologous to gyrB of topoisomerase II. More information about this protein can be found at Protein of the Month: DNA Topoisomerase .; GO: 0003677 DNA binding, 0003918 DNA topoisomerase (ATP-hydrolyzing) activity, 0005524 ATP binding, 0006265 DNA topological change, 0005694 chromosome.

Probab=94.58  E-value=0.12  Score=30.39  Aligned_cols=86  Identities=10%  Similarity=0.153  Sum_probs=54.9

Q ss_pred             CHHHHHHHHHHHHHHHHHHH--HHCCCCCCCCCCCCCEEEEEEECCCCCCCH--H-----HHHHHH----------CCCC
Q ss_conf             00123444567664687653--200111112355772047999878984402--4-----588740----------5454
Q gi|254780891|r  112 SRERAKILLNLFMVAHASLP--RGGKVTISVQDSKNENIFSLKINGNLARFP--E-----KFTQIV----------DGNV  172 (215)
Q Consensus       112 ~~~~~qvl~NLi~NA~~a~~--~gg~I~i~~~~~~~~~~i~V~D~G~Gi~~~--e-----~~~~~~----------~~~~  172 (215)
T Consensus        38 s~GLHHl~wEIvdNsvDEvl~g~a~~I~V~l~~dns---i~V~D~GRG~P~~~h~~~~isT~e~vlT~LHAGGKFd~~~Y  114 (655)
T TIGR01058        38 SKGLHHLVWEIVDNSVDEVLAGYADNITVTLHKDNS---ISVQDDGRGIPTGIHKQGKISTVETVLTVLHAGGKFDQGGY  114 (655)
T ss_pred             CCCCHHHHHHHHHHHHHHHHHCCCCEEEEEEECCCE---EEEEECCCCCCCCHHCCCCCCCCCEEEEEEECCCCCCCCCE
T ss_conf             785055678788446888982269747999827870---78875785376012216898851004544307730378650


Q ss_pred             CCCCCCCCHHHHHHHHHHHHCCCEEEEEEECC
Q ss_conf             57899872049999999997098799998779
Q gi|254780891|r  173 ESTIDSHDIQFYYVILLAHENKIRLLPEIIDD  204 (215)
Q Consensus       173 ~~~~~g~GlGl~~~~~i~~~~gG~i~v~~~~~  204 (215)
T Consensus       115 KtaGGLHGVGa----SVVNALS~wL~v~v~Rd  142 (655)
T TIGR01058       115 KTAGGLHGVGA----SVVNALSSWLEVEVKRD  142 (655)
T ss_pred             EECCCCCCCHH----HHHHHCCCCEEEEEEEC
T ss_conf             10573223036----77640226338999878