Sandbox Reserved 199: Difference between revisions
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A 3D NMR structure was obtained with a backbone RMSD of 1.07Å. The obtained model shows a similar tertiary structure to the kidney bean shaped RNase A and is stabilized by four <scene name='Sandbox_Reserved_199/2k11_disulfide_bonds/1'>disulfide bonds</scene>. The structure shows three <scene name='Sandbox_Reserved_199/2k11_alpha_helix/2'>α-helices</scene> and seven <scene name='Sandbox_Reserved_199/2k11_beta_sheets/1'>β-sheets</scene>. While this structure matches up fairly well with previous X-Ray crystallography structures of RNase 1, important differences in residue positioning can be seen in the <scene name='Sandbox_Reserved_199/2k11_all_models/3'>3D NMR structure</scene> which are not apparent in X-Ray crystallography. Specifically, certain residues with more flexibility undergo a significant conformational change when bound to certain substrates, such as the human ribonuclease inhibitor (HcrI). These residues include: <scene name='Sandbox_Reserved_199/2k11_flexible_residues/1'>Arg 4, Lys 6, Arg 32, Arg 39, and Lys 102</scene>. | A 3D NMR structure was obtained with a backbone RMSD of 1.07Å. The obtained model shows a similar tertiary structure to the kidney bean shaped RNase A and is stabilized by four <scene name='Sandbox_Reserved_199/2k11_disulfide_bonds/1'>disulfide bonds</scene>. The structure shows three <scene name='Sandbox_Reserved_199/2k11_alpha_helix/2'>α-helices</scene> and seven <scene name='Sandbox_Reserved_199/2k11_beta_sheets/1'>β-sheets</scene>. While this structure matches up fairly well with previous X-Ray crystallography structures of RNase 1, important differences in residue positioning can be seen in the <scene name='Sandbox_Reserved_199/2k11_all_models/3'>3D NMR structure</scene> which are not apparent in X-Ray crystallography. Specifically, certain residues with more flexibility undergo a significant conformational change when bound to certain substrates, such as the human ribonuclease inhibitor (HcrI). These residues include: <scene name='Sandbox_Reserved_199/2k11_flexible_residues/1'>Arg 4, Lys 6, Arg 32, Arg 39, and Lys 102</scene>. | ||
This data suggests an “induced-fit” model of substrate binding and may prove vital to fully understanding RNase 1’s binding specificity for Hcrl; although two residues, | This data suggests an “induced-fit” model of substrate binding and may prove vital to fully understanding RNase 1’s binding specificity for Hcrl; although two residues, <scene name='Sandbox_Reserved_199/2k11_42_43/1'>Pro 42 and Val43</scene>, show much more rigidity and possibly contribute some “lock-and-key” binding interaction. | ||
[[Image:Kroupa Ribonuclease inhibitor.png|thumb |right |alt=RNase Inhibitor. |Example Ribonuclease inhibitor structure.]] | [[Image:Kroupa Ribonuclease inhibitor.png|thumb |right |alt=RNase Inhibitor. |Example Ribonuclease inhibitor structure.]] | ||
