DNA supercoiling is an important determinant of variety
of molecular processes because of its influence on substrate
properties of DNA. Many proteins that bind DNA interact in
a negatively supercoil dependent manner. The higher free
energy associated with negative supercoiling is utilized for
binding and subsequent transactions. Protein components of
DNA replication, segregation, transcription and
recombination machinery interact with DNA in topology
dependent manner. Topoisomerases, thus play essential role
in DNA transaction processes. Owing to their influence on
diverse cellular functions, the enzymes are considered as
global regulators. Movement of macromolecular assemblies
along the DNA helix generates internal torsional strain
during replication and transcription. This strain manifests
itself as local domains of supercoils ahead and behind the
helix tracking machinery. If left unchecked, accumulation of
these supercoils could severely affect the survival of the
cells. Cellular systems thus employ more than one
topoisomerase, which act in concert to regulate DNA
topology and maintain a steady-state level of supercoiling
necessary for integrity and functionality of DNA molecules.
| Identifer | oai:union.ndltd.org:METU/oai:etd.lib.metu.edu.tr:http://etd.lib.metu.edu.tr/upload/12605440/index.pdf |
| Date | 01 October 2004 |
| Creators | Candemir, Guray Fehmi |
| Contributors | Deren, Ahmet |
| Publisher | METU |
| Source Sets | Middle East Technical Univ. |
| Language | English |
| Detected Language | English |
| Type | M.S. Thesis |
| Format | text/pdf |
| Rights | To liberate the content for public access |
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