Sandbox Reserved 967: Difference between revisions
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H2C protein is found in the middle of the elongated complex structure, flanked by H2A and H2B proteins on the ends. | H2C protein is found in the middle of the elongated complex structure, flanked by H2A and H2B proteins on the ends. | ||
The complex is stabilized by the intimately interwoven architecture of H2B and H2C: The N-terminal region of H2B protein (amino acids 1-92) weaves together with H2C domain to form 3 β-barrels, also called “triple barrel”<ref name ="ref9"> Nicholson, Allen W. Ribonucleases. Springer Science & Business Media, 2011.</ref>. This triple barrel is formed from a total of 18 β-sheets and produces a pseudo-2-fold axis of symmetry along the central barrel. Also, it permits to leave the mostly α-helical C-terminal region of H2B available for potential interactions with other protein (for example the PCNA protein). Finally, it has been found that the motif provides a platform for securely binding the H2A protein: the side and end of the first barrel in the subcomplex H2B/H2C form a <scene name='60/604486/Tight_interface_h2ah2c/2'>tight interface</scene> with amino acids 197-258 in the C-terminal region of H2A protein. This interface is composed mainly of hydrophobic residues<ref name="ref5">. | The complex is stabilized by the intimately interwoven architecture of H2B and H2C: The N-terminal region of H2B protein (amino acids 1-92) weaves together with H2C domain to form 3 β-barrels, also called “triple barrel”<ref name ="ref9"> Nicholson, Allen W. Ribonucleases. Springer Science & Business Media, 2011.</ref>. This triple barrel is formed from a total of 18 β-sheets and produces a pseudo-2-fold axis of symmetry along the central barrel. Also, it permits to leave the mostly α-helical C-terminal region of H2B available for potential interactions with other protein (for example the PCNA protein). Finally, it has been found that the motif provides a platform for securely binding the H2A protein: the side and end of the first barrel in the subcomplex H2B/H2C form a <scene name='60/604486/Tight_interface_h2ah2c/2'>tight interface</scene> with amino acids 197-258 in the C-terminal region of H2A protein. This interface is composed mainly of hydrophobic residues<ref name="ref5">. | ||
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It is important to notice that the Mammalian RNase H2 contains only one cleft with the active site for substrate binding: RNase H2 may recognize single ribonucleotide within a DNA duplex that have a B-form helical structure, as well as longer RNA in RNA-DNA hybrid which adopts intermediate A/B form structure. Thus, the RNase H2 enzyme needs to bind both conformations to able to fully complete all its roles. | It is important to notice that the Mammalian RNase H2 contains only one cleft with the active site for substrate binding: RNase H2 may recognize single ribonucleotide within a DNA duplex that have a B-form helical structure, as well as longer RNA in RNA-DNA hybrid which adopts intermediate A/B form structure. Thus, the RNase H2 enzyme needs to bind both conformations to able to fully complete all its roles. | ||
== Activity == | == Activity == | ||
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* '''2''' : In line attack by hydroxide ion of the target phosphate. During this step, a pentacovalent phosphate (transition state) is formed and stabilized by metal MA++ by interacting with both the nonbridging and 3' bridging oxygen. ['''Je dois rajouter ce qu'il y a dans le tableau ?'''] | * '''2''' : In line attack by hydroxide ion of the target phosphate. During this step, a pentacovalent phosphate (transition state) is formed and stabilized by metal MA++ by interacting with both the nonbridging and 3' bridging oxygen. ['''Je dois rajouter ce qu'il y a dans le tableau ?'''] | ||
* '''3''' : The cleaved phosphate cannot simultaneously coordinate the two metal ions anymore, and likely one of the metal ions leave the active site which triggers a release of cleave product. | * '''3''' : The cleaved phosphate cannot simultaneously coordinate the two metal ions anymore, and likely one of the metal ions leave the active site which triggers a release of cleave product. | ||
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. | ||
</ | |||
</StructureSection> | |||
== References == | == References == | ||
<references/> | <references/> | ||
