Sandbox Reserved 967: Difference between revisions
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The RNase H2 recognize 2’OH group of ribonucleotides in RNA at RNA/DNA junction and cannot cleave unhybridized RNA. The phosphodiester hydrolysis catalysed by the RNase H2 is likely following a two-metal ion-dependent mechanism quite common for phosphoryl hydrolases like RNase H enzymes. | The RNase H2 recognize 2’OH group of ribonucleotides in RNA at RNA/DNA junction and cannot cleave unhybridized RNA. The phosphodiester hydrolysis catalysed by the RNase H2 is likely following a two-metal ion-dependent mechanism quite common for phosphoryl hydrolases like RNase H enzymes. | ||
The active site of the catalytic H2A protein is located in a cleft near one end of the complex and formed by strands β2 and 5, and helices α4 and α5. The active site contains four catalytic amino acids strictly conserved in RNases H2: <scene name='60/604486/Site_actif/1'>Asp34, Glu35, Asp142 and Asp170/scene>. These amino acids are essential for the coordination of the 2 divalent metal ions implicated in the stabilisation of reaction intermediates and transition states. In vitro, these ions can be Mg++, Mn++ or Zn++ but the native enzyme is likely to contain Mg++. | The active site of the catalytic H2A protein is located in a cleft near one end of the complex and formed by strands β2 and 5, and helices α4 and α5. The active site contains four catalytic amino acids strictly conserved in RNases H2: <scene name='60/604486/Site_actif/1'>Asp34, Glu35, Asp142 and Asp170</scene>. These amino acids are essential for the coordination of the 2 divalent metal ions implicated in the stabilisation of reaction intermediates and transition states. In vitro, these ions can be Mg++, Mn++ or Zn++ but the native enzyme is likely to contain Mg++. | ||
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