Fumarase 2: Difference between revisions

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== Active Site Characteristics ==

The active site (A-site) of the fumarase enzyme is formed by residues from three of the enzyme’s four subunits (shown in <scene name='44/446278/Active_site_chains/2'>different colors</scene>) and is located in a relatively deep pit that is removed from bulk solvent <ref>PMID: 7552727</ref>. The residues that form the <scene name='44/446278/Active_site_residues/1'>active site</scene> include N141b, T100b, S98b, E331c, K324c, N326c, His 188c, (the letter indicates the chain) and a water molecule. It is speculated that the <scene name='44/446278/His_188_active_site/1'>H188</scene> is the most important active site residue, activating the water through a <scene name='44/446278/Short_h_bond/1'>short hydrogen bond</scene>, which increases the basicity of the water molecule. This electron-withdrawing hydrogen bond allows the water molecule to remove the C3 proton of malate, though this model has <scene name='44/446278/Citrate/1'>citrate</scene> in the active site. Complex hydrogen bonding patterns in the active site ~~involving T187, N141, H188, N362, and K324~~ also help stabilize the aci-carboxylate intermediate<ref name= "Weaver">PMID:9098893</ref>. By increasing the stabilization if the intermediate, the fumarase enzyme can effectively catalyze the hydration/dehydration reaction between L-malate and fumarate.

The active site (A-site) of the fumarase enzyme is formed by residues from three of the enzyme’s four subunits (shown in <scene name='44/446278/Active_site_chains/2'>different colors</scene>) and is located in a relatively deep pit that is removed from bulk solvent <ref>PMID: 7552727</ref>. The residues that form the <scene name='44/446278/Active_site_residues/1'>active site</scene> include N141b, T100b, S98b, E331c, K324c, N326c, His 188c, (the letter indicates the chain) and a water molecule. It is speculated that the <scene name='44/446278/His_188_active_site/1'>H188</scene> is the most important active site residue, activating the water through a <scene name='44/446278/Short_h_bond/1'>short hydrogen bond</scene>, which increases the basicity of the water molecule. This electron-withdrawing hydrogen bond allows the water molecule to remove the C3 proton of malate, though this model has <scene name='44/446278/Citrate/1'>citrate</scene> in the active site. Complex hydrogen bonding patterns in the active site also help stabilize the aci-carboxylate intermediate<ref name= "Weaver">PMID:9098893</ref>. By increasing the stabilization if the intermediate, the fumarase enzyme can effectively catalyze the hydration/dehydration reaction between L-malate and fumarate.

Fumarase 2: Difference between revisions

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Revision as of 23:03, 10 February 2018 view source Ann Taylor (talk \| contribs) 1,015 edits No edit summary ← Older edit		Revision as of 23:43, 10 February 2018 view source Ann Taylor (talk \| contribs) 1,015 edits mNo edit summary Newer edit →
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	== Active Site Characteristics ==		== Active Site Characteristics ==
	The active site (A-site) of the fumarase enzyme is formed by residues from three of the enzyme’s four subunits (shown in <scene name='44/446278/Active_site_chains/2'>different colors</scene>) and is located in a relatively deep pit that is removed from bulk solvent <ref>PMID: 7552727</ref>. The residues that form the <scene name='44/446278/Active_site_residues/1'>active site</scene> include N141b, T100b, S98b, E331c, K324c, N326c, His 188c, (the letter indicates the chain) and a water molecule. It is speculated that the <scene name='44/446278/His_188_active_site/1'>H188</scene> is the most important active site residue, activating the water through a <scene name='44/446278/Short_h_bond/1'>short hydrogen bond</scene>, which increases the basicity of the water molecule. This electron-withdrawing hydrogen bond allows the water molecule to remove the C3 proton of malate, though this model has <scene name='44/446278/Citrate/1'>citrate</scene> in the active site. Complex hydrogen bonding patterns in the active site ~~involving T187, N141, H188, N362, and K324~~ also help stabilize the aci-carboxylate intermediate<ref name= "Weaver">PMID:9098893</ref>. By increasing the stabilization if the intermediate, the fumarase enzyme can effectively catalyze the hydration/dehydration reaction between L-malate and fumarate.		The active site (A-site) of the fumarase enzyme is formed by residues from three of the enzyme’s four subunits (shown in <scene name='44/446278/Active_site_chains/2'>different colors</scene>) and is located in a relatively deep pit that is removed from bulk solvent <ref>PMID: 7552727</ref>. The residues that form the <scene name='44/446278/Active_site_residues/1'>active site</scene> include N141b, T100b, S98b, E331c, K324c, N326c, His 188c, (the letter indicates the chain) and a water molecule. It is speculated that the <scene name='44/446278/His_188_active_site/1'>H188</scene> is the most important active site residue, activating the water through a <scene name='44/446278/Short_h_bond/1'>short hydrogen bond</scene>, which increases the basicity of the water molecule. This electron-withdrawing hydrogen bond allows the water molecule to remove the C3 proton of malate, though this model has <scene name='44/446278/Citrate/1'>citrate</scene> in the active site. Complex hydrogen bonding patterns in the active site also help stabilize the aci-carboxylate intermediate<ref name= "Weaver">PMID:9098893</ref>. By increasing the stabilization if the intermediate, the fumarase enzyme can effectively catalyze the hydration/dehydration reaction between L-malate and fumarate.