Topoisomerase I is an enzyme that plays a crucial role in DNA replication and transcription. The spelling of the word "Topoisomerase I" can be explained using IPA phonetic transcription as /tɒpəʊaɪsəˌmɛrəseɪs wʌn/. The first syllable "topo" represents the prefix meaning "location" or "place." The second syllable "iso" means "same" or "equal." The suffix "merase" refers to the enzyme's function of adding or removing specific molecules. The numeral one represents a specific isoform of the enzyme. Overall, this complex word reflects the enzyme's complex and important role in DNA metabolism.
Topoisomerase I is an essential enzyme found in living organisms that plays a critical role in DNA replication and transcription. It is a type of topoisomerase enzyme that specifically acts on single-stranded DNA molecules. Topoisomerases are enzymes responsible for manipulating the supercoiling and winding/unwinding of DNA, which is necessary for various cellular processes.
Topoisomerase I catalyzes the reversible cleavage and rejoining of one DNA strand, relieving the torsional strain caused by the twist and supercoiling of the DNA molecule. By breaking a phosphodiester bond in one strand of the DNA, the enzyme allows it to rotate freely around the intact strand, relaxing the supercoiling. After the process is completed, topoisomerase I re-ligates the cleaved DNA strand back together, restoring the integrity of the DNA molecule.
This enzymatic activity of topoisomerase I is crucial for DNA replication, as it enables the replication machinery to access the DNA strands and separate them during the replication process. It is also involved in transcription, regulating the initiation and elongation of RNA synthesis by influencing the supercoiling state of the DNA template.
Topoisomerase I inhibitors are a class of drugs used in cancer treatments. These inhibitors interfere with the DNA repair process and prevent the re-ligation of the cleaved DNA strands, thereby causing DNA damage and cell death. They have shown effectiveness against various types of cancer, making topoisomerase I an important target for the development of anti-cancer drugs.
The word "Topoisomerase I" is derived from a combination of different terms:
1. Topo-: It comes from the Greek root "topo", meaning "place" or "location".
2. Isomer-: It originates from the Greek word "isomeres", meaning "having equal parts" or "equal in measure".
3. -ase: It is a common suffix used to denote an enzyme.
So, when combined, "Topoisomerase" can be loosely translated to mean an enzyme that acts on the location or arrangement of molecules.
The "I" in "Topoisomerase I" indicates that it is the first enzyme in the topoisomerase family to be discovered or characterized. There are multiple types of topoisomerases, identified by Roman numerals (e.g.