Sandbox GGC15
From Proteopedia
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==DNA TOPOISOMERASE I== | ==DNA TOPOISOMERASE I== | ||
<StructureSection load='1A36' size='340' side='right' caption='Caption for this structure' scene=''> | <StructureSection load='1A36' size='340' side='right' caption='Caption for this structure' scene=''> | ||
| - | Eukaryotic DNA topoisomerase I (topo I) is a protein that reduces the strain from the supercoils that are caused during transcription and translation<ref name=" | + | Eukaryotic DNA topoisomerase I (topo I) is a protein that reduces the strain from the supercoils that are caused during transcription and translation<ref name="Staker et al., 2002">DOI 10.1073/pnas.242259599</ref>. There are two types of topoisomerases. Type 1 topoisomerases are monomeric and break one strand of DNA<ref name="Redinbo et al., 1998">PMID:9488644</ref>. Type 2 topoisomerases are dimeric, meaning that they made up of two units and break both strands of the DNA helix<ref name="Redinbo et al., 1998" />. They are able to pass another part of the duplex through the cut, and close the cut using ATP<ref name="Staker et al., 2002" />. |
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| + | == Structure == | ||
| + | Human topo 1 is composed of 765 amino acids <ref name="Redinbo et al., 1998" />. The enzyme consist of 4 regions which are the NH2-terminal, core, linker, and COOH-terminal domains<ref name="Redinbo et al., 1998" />. The NH2-terminal is aprroximately 210 residues long, it is highly charged, disordered, and contains few hydrophobic amino acids<ref name="Redinbo et al., 1998" />. The COOH-terminal domain is made up of residues 713 to 765 and contains the important amino aside Tyrosine 223<ref name="Redinbo et al., 1998" />. The location of the active site is at this amino acid<ref name="Redinbo et al., 1998" />. The active site is catalytic and forms a phosphoester bond with the 3' phosphate at the site of cleavage on the DNA strand<ref name="Redinbo et al., 1998" />. | ||
== Disease == | == Disease == | ||
== Relevance == | == Relevance == | ||
| + | Many anticancer drugs target topo 1 enzymes. | ||
== Structural highlights == | == Structural highlights == | ||
Revision as of 21:07, 27 April 2021
DNA TOPOISOMERASE I
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References
- ↑ 1.0 1.1 Staker BL, Hjerrild K, Feese MD, Behnke CA, Burgin AB Jr, Stewart L. The mechanism of topoisomerase I poisoning by a camptothecin analog. Proc Natl Acad Sci U S A. 2002 Nov 26;99(24):15387-92. Epub 2002 Nov 8. PMID:12426403 doi:10.1073/pnas.242259599
- ↑ 2.0 2.1 2.2 2.3 2.4 2.5 2.6 2.7 Redinbo MR, Stewart L, Kuhn P, Champoux JJ, Hol WG. Crystal structures of human topoisomerase I in covalent and noncovalent complexes with DNA. Science. 1998 Mar 6;279(5356):1504-13. PMID:9488644
