Sandbox Reserved 1846: Difference between revisions
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[[Image:Final rayed image of binding pocket.png|400 px|right|thumb|Figure 1: Ser, His, Asp catalytic triad non-covalent stabilizing interactions with oxyanion hole.]] | [[Image:Final rayed image of binding pocket.png|400 px|right|thumb|Figure 1: Ser, His, Asp catalytic triad non-covalent stabilizing interactions with oxyanion hole.]] | ||
LCC catalyzes the breakdown of PET using a serine hydrolase mechanism with a <scene name='10/1075247/Catalytic_triad3_w_label/3'>catalytic triad</scene> of Ser165, His242, and Asp210. (Figure 1) (1) The reaction begins when His242 deprotonates Ser165, which activates it as a nucleophile. (2) Ser165 then attacks the carbonyl carbon of an ester bond in the PET polymer to form a tetrahedral transition state. This transition state is stabilized by an oxyanion hole formed by the backbone amides of Met166 and Tyr95. (3) Proton transfer then leads to formation of semi-stable acyl-enzyme intermediate and the alcohol product. (4) A water molecule, activated by His242, then attacks the acyl-enzyme. This releases the second product and resets the enzyme’s active site. 5) | LCC catalyzes the breakdown of PET using a serine hydrolase mechanism with a <scene name='10/1075247/Catalytic_triad3_w_label/3'>catalytic triad</scene> of Ser165, His242, and Asp210. (Figure 1) (1) The reaction begins when His242 deprotonates Ser165, which activates it as a nucleophile. (2) Ser165 then attacks the carbonyl carbon of an ester bond in the PET polymer to form a tetrahedral transition state. This transition state is stabilized by an oxyanion hole formed by the backbone amides of Met166 and Tyr95. (3) Proton transfer then leads to formation of semi-stable acyl-enzyme intermediate and the alcohol product. (4) A water molecule, activated by His242, then attacks the acyl-enzyme. This releases the second product and resets the enzyme’s active site. 5) | ||
[[Image: | [[Image:FinalMechanism2.jpg|800 px|right|thumb|Figure 2: LCC mechanism. LCC hydrolyzes PET using a catalytic triad (Ser165, His242, Asp210) to cleave its ester bonds via two tetrahedral transition states to an acyl-enzyme intermediate.]] | ||
=== Ligand Binding Pocket === | === Ligand Binding Pocket === | ||
