Sandbox Wabash 28 Fumarase
From Proteopedia
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==Fumarase's debated active site== | ==Fumarase's debated active site== | ||
| - | <scene name='72/726358/Fumarase_intro_image/1'>Wild type fumarase</scene> is a highly conserved enzyme found in bacteria as well as mitochondria of eukaryotes which catalyzes the hydration/dehydration of fumarate and L-malate, respectively. The protein, which consists of two dimers laden with α-helices, initially crystalized as a dimer making conclusions about its active site problematic. However, subsequent crystalizations with various inhibitors showed two potential active sites - the locations at which the inhibitors bound: the first discovered theoretical active site <scene name='72/726358/Fumarase_site_a_his_188/1'>(A)</scene> is located deep in the interior of the tetramer and was inhibited by pyromelletic acid and citrate - the latter of which is found in the potential active site; β-trimethylsilyl maleate inhibition resulted in the discover of <scene name='72/726358/Fumarase_b_site_h129/1'>site B</scene> found at the exterior of each subunit. In either case, a basic His residue is believed to be the origin of catalytic function and two such residues were found (His 188 in site A and His 129 in site B). To conclusively determine whether A or B is the active site, site-directed mutagenesis in E. coli was conducted. | + | <scene name='72/726358/Fumarase_intro_image/1'>Wild type fumarase</scene> is a highly conserved enzyme found in bacteria as well as mitochondria of eukaryotes which catalyzes the hydration/dehydration of fumarate and L-malate, respectively. The protein, which consists of two dimers laden with α-helices, initially crystalized as a dimer making conclusions about its active site problematic. However, subsequent crystalizations with various inhibitors showed two potential active sites - the locations at which the inhibitors bound: the first discovered theoretical active site <scene name='72/726358/Fumarase_site_a_his_188/1'>(A)</scene> is located deep in the interior of the tetramer and was inhibited by pyromelletic acid and citrate - the latter of which is found in the potential active site; β-trimethylsilyl maleate inhibition resulted in the discover of <scene name='72/726358/Fumarase_b_site_h129/1'>site B</scene> found at the exterior of each subunit. In either case, a basic His residue is believed to be the origin of catalytic function and two such residues were found (His 188 in site A and His 129 in site B). To conclusively determine whether A or B is the active site, site-directed mutagenesis in ''E. coli'' was conducted. |
| - | + | ==Theoretical mechanism== | |
| - | + | L-malate is believed to be dehydrated by fumarase into fumarate using basic residues in its active site. | |
| - | + | [[Image:[[File:Fumarase mechanism.jpg|thumb|Fumarase mechanism for dehydrating L-malate into fumarate]]]] | |
| - | + | ||
== References == | == References == | ||
<references/> | <references/> | ||
Revision as of 00:02, 28 February 2016
Fumarase's debated active site
is a highly conserved enzyme found in bacteria as well as mitochondria of eukaryotes which catalyzes the hydration/dehydration of fumarate and L-malate, respectively. The protein, which consists of two dimers laden with α-helices, initially crystalized as a dimer making conclusions about its active site problematic. However, subsequent crystalizations with various inhibitors showed two potential active sites - the locations at which the inhibitors bound: the first discovered theoretical active site is located deep in the interior of the tetramer and was inhibited by pyromelletic acid and citrate - the latter of which is found in the potential active site; β-trimethylsilyl maleate inhibition resulted in the discover of found at the exterior of each subunit. In either case, a basic His residue is believed to be the origin of catalytic function and two such residues were found (His 188 in site A and His 129 in site B). To conclusively determine whether A or B is the active site, site-directed mutagenesis in E. coli was conducted.
Theoretical mechanism
L-malate is believed to be dehydrated by fumarase into fumarate using basic residues in its active site. [[Image:thumb|Fumarase mechanism for dehydrating L-malate into fumarate]]
