Topoisomerase IV subunit B is a protein component of the enzyme topoisomerase IV. Topoisomerase IV is a type II topoisomerase enzyme found in bacteria and other microorganisms. It plays a crucial role in DNA replication, recombination, and repair by facilitating changes in the topology of DNA molecules.
The function of topoisomerase IV subunit B is to assist in the catalytic activity of the topoisomerase IV enzyme complex. It works in conjunction with other subunits, specifically subunit A, to carry out the enzymatic reactions required for DNA topology modifications. Subunit B is responsible for binding to DNA and locating the target sites for the enzyme action.
When topoisomerase IV cleaves the DNA strands, subunit B ensures that the strands are correctly aligned to prevent DNA damage or improper rejoining. It also aids in the process of DNA strand passage, where the enzyme passes one DNA double helix through another to relieve supercoiling or entanglement.
Furthermore, topoisomerase IV subunit B also plays a crucial role in the separation of replicated DNA molecules during bacterial cell division. It helps to decatenate the intertwined DNA strands, ensuring proper segregation of chromosomes into daughter cells.
In summary, topoisomerase IV subunit B is a key component of the topoisomerase IV enzyme complex that is involved in DNA replication, recombination, and repair. Its function is to assist in the catalytic reactions of this enzyme, ensuring proper DNA topology modifications and chromosomal segregation.
