>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=93.34  E-value=0.15  Score=29.18  Aligned_cols=44  Identities=16%  Similarity=0.141  Sum_probs=29.9

Q ss_pred             HHHCCCCEEEEEEEEECCCCCEEEEEEEEEEEEECCCEEEEEEE
Q ss_conf             97248984899999886989889988999999837960699999
Q gi|254780903|r  320 VTGKHVKQLDQIFHMRHASGADIWIQVRAQMMRTISGGMNIIGI  363 (766)
Q Consensus       320 ~~~~~~~~~~~e~Ri~~~DG~~~Wi~~r~~~i~d~~G~~~~iGi  363 (766)
T Consensus       248 ~f~ge~~~i~Ve~afQfnd~~~e~ilSF~N~vkT~eGG~HE~g~  291 (655)
T TIGR01058       248 YFEGEKNGIEVEVAFQFNDGDSENILSFANSVKTKEGGTHENGF  291 (655)
T ss_pred             EEEECCCCEEEEEEEEECCCCCCEEEEEEEEEEECCCCCCHHHH
T ss_conf             88764762589999974278875379864003406887207889