Sandbox Reserved 194: Difference between revisions
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== '''Ribonuclease A Substrate Binding''' == | == '''Ribonuclease A Substrate Binding''' == | ||
<Structure load='1RTA' size='450' frame='true' align='right' caption=' | <Structure load='1RTA' size='450' frame='true' align='right' caption='Thymidylic acid tetramer and ApTpApApG complexed with ribonuclease A showing pi stacking and hydrogen bonding ' scene='Sandbox_Reserved_194/1rta_just_dt/1' /> | ||
RNA degradation and formation is essential in protein regulation within the body. RNase A is an endonuclease that cleaves and breaks down RNA through attack at its 2’OH. It has served as a model providing insight into the stability, folding and chemistry of proteins. | |||
[[Image:1RTA_zoom.png|thumb|left|275px|Thymidylic acid tetramer complexed with ribonuclease A]] | |||
To determine the structural characteristics of RNA substrate binding to RNase A, X-ray crystallography was used to image inhibitory DNA tetramers bound to the enzyme. DNA lacks the 2′OH essential to RNA cleavage, making the complex more conducive to crystallography. In previous studies, <scene name='Sandbox_Reserved_194/1rta_structure/1'> | To determine the structural characteristics of RNA substrate binding to RNase A, X-ray crystallography was used to image inhibitory DNA tetramers bound to the enzyme. DNA lacks the 2′OH essential to RNA cleavage, making the complex more conducive to crystallography. In previous studies, <scene name='Sandbox_Reserved_194/1rta_structure/1'> | ||
the RNase A - thymidylic acid tetramer (d(pT)4) complex</scene> has provided information into the specificity of the binding pocket subunits, B0, B1, B2 and B3. Many interactions observed in this complex occur between amino acid residues and the nucleic acid backbone such as hydrogen bonding between the A1 ribose and Thr78. Because of the interactions with the N3 and Thr45 in the B1 position, it appears this site is exclusive to pyrimidines. ‘<ref>PMID:1429575</ref>’ | the RNase A - thymidylic acid tetramer (d(pT)4) complex</scene> has provided information into the specificity of the binding pocket subunits, B0, B1, B2 and B3. Many interactions observed in this complex occur between amino acid residues and the nucleic acid backbone such as hydrogen bonding between the A1 ribose and Thr78. Because of the interactions with the N3 and Thr45 in the B1 position, it appears this site is exclusive to pyrimidines. ‘<ref>PMID:1429575</ref>’ | ||
[[Image:1RCN_zoom.png|thumb|left| | [[Image:1RCN_zoom.png|thumb|left|275px|ApTpApApG complexed with ribonuclease A]] | ||
Further binding pocket characterization was accomplished using the oglionucleotide <scene name='Sandbox_Reserved_194/1rcn_just_dtda/1'>d(ApTpApApG)</scene>. | Further binding pocket characterization was accomplished using the oglionucleotide <scene name='Sandbox_Reserved_194/1rcn_just_dtda/1'>d(ApTpApApG)</scene>. | ||
While binding of other nucleobases to the B2 and B3 sites is possible, the imaging of this <scene name='Sandbox_Reserved_194/1rcn_structure/2'>complex </scene>elucidated the preferences | While binding of other nucleobases to the B2 and B3 sites is possible, the imaging of this <scene name='Sandbox_Reserved_194/1rcn_structure/2'>complex </scene>elucidated the preferences | ||
