Sandbox GGC15: Difference between revisions
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== Structure == | == Structure == | ||
Human topo 1 is composed of 765 amino acids <ref name="Redinbo" />. The enzyme consist of 4 regions which are the NH2-terminal, core, linker, and COOH-terminal domains<ref name="Redinbo" />. The NH2-terminal is approximately 210 residues long, it is highly charged, disordered, and contains few hydrophobic amino acids<ref name="Redinbo" />. The COOH-terminal domain is made up of residues 713 to 765 and contains the important amino aside Tyrosine 223<ref name="Redinbo"/>. The location of the active site is at this amino acid<ref name="Redinbo" />. | Human topo 1 is composed of 765 amino acids <ref name="Redinbo" />. The enzyme consist of 4 regions which are the NH2-terminal, core, linker, and COOH-terminal domains<ref name="Redinbo" />. The NH2-terminal is approximately 210 residues long, it is highly charged, disordered, and contains few hydrophobic amino acids<ref name="Redinbo" />. The COOH-terminal domain is made up of residues 713 to 765 and contains the important amino aside Tyrosine 223<ref name="Redinbo"/>. The location of the active site is at this amino acid<ref name="Redinbo" />. | ||
== Active Site == | == Active Site == | ||
Topo 1 reduces stress in DNA by causing a transient single strand nick in the the DNA helix<ref name="Staker" />. This nick enables the cut to rotate around its intact complement, thus eliminating proximal supercoils<ref name="Staker" />. | |||
The active site is catalytic and | |||
The active site of Topo 1 is catalytic and it is the location where the nicking or cutting occurs<ref name="Redinbo" />. The nicking occurs from the trans-esterification of Tyr-723 at a DNA phophodiester bond forming a 3�-phosphotyrosine covalent enzyme–DNA complex <ref name="Staker" />. After the DNA is relaxed, the covalent intermediate is reversed when the released 5�-OH of the broken strand reattacks the phosphotyrosine intermediate in a second transesterification reaction<ref name="Staker" />. | |||
== Relevance == | == Relevance == | ||
Many anticancer drugs target topo 1 enzymes. | Many anticancer drugs target topo 1 enzymes. | ||
== | == Mutations == | ||
This is a sample scene created with SAT to <scene name="/12/3456/Sample/1">color</scene> by Group, and another to make <scene name="/12/3456/Sample/2">a transparent representation</scene> of the protein. You can make your own scenes on SAT starting from scratch or loading and editing one of these sample scenes. | This is a sample scene created with SAT to <scene name="/12/3456/Sample/1">color</scene> by Group, and another to make <scene name="/12/3456/Sample/2">a transparent representation</scene> of the protein. You can make your own scenes on SAT starting from scratch or loading and editing one of these sample scenes. | ||
