Sandbox 47: Difference between revisions

Horse pancreatic lipase (PDB ID-1hpl) is an asymmetrical molecule that consists of two subunits, each of which contain 449 amino acids and 705 well-defined water molecules. The two subunits, <scene name='Sandbox_47/Chain_a/3'>TextToBeDisplayed</scene> and <scene name='Sandbox_47/Lipasechainb/1'>B</scene>, interact through a variety of <scene name='Sandbox_47/Lipasecontacts/1'>contacts</scene>. The subunits are related by a 2-fold non-crystallographic symmetry axis. Lipase also binds two <scene name='Sandbox_47/Lipase_calcium/2'>calcium ions</scene> as ligands through a variety of <scene name='Sandbox_47/Calciumcontacts/4'>contacts</scene>. Its <scene name='Sandbox_47/Lipasesecondarystructures/1'>secondary structure</scene> consists of 22% <scene name='Sandbox_47/Lipase_helix/2'>helices</scene> and 30% <scene name='Sandbox_47/Lipase_sheet/2'>beta sheets</scene>. It contains both <scene name='Sandbox_47/Lipase_hydrophobicres/2'>hydrophobic</scene> (red) and <scene name='Sandbox_47/Lipase_polarres/1'>polar residues</scene> (blue). The overall molecular structure of horse lipase has two well-defined domains. The <scene name='Sandbox_47/Nterminal/1'>N-terminal</scene> domain (residues 1-336) contains the <scene name='Sandbox_47/Activesite/4'>active site</scene> and has a typical alpha/beta hydrolase fold topology. The active site contains a catalytic triad (Ser-152, Asp-176, and His-263) that closely resembles that of serine proteases. The N-terminal domain also contains a <scene name='Sandbox_47/Lid/1'>"lid"</scene> that blocks solvent from entering the active site. The <scene name='Sandbox_47/Cterminal/1'>C-terminal</scene> domain (residues (337-449), for colipase binding, has a beta-sheet sandwich topology.<ref>Bourne Y, Martinez C, Kerfelec B, Lombardo D, Chapus C, Cambillau C. 1994. Horse pancreatic lipase. J. mol Biol. 238: 709-732.</ref>