Sandbox Reserved 771: Difference between revisions

← Older edit Newer edit →

Proteopedia Page Contributors and Editors (what is this?)Proteopedia Page Contributors and Editors (what is this?)

OCA, Elliott Wyatt

@@ Line 7: / Line 7: @@
 [[Image:Dimerized_color.jpg|left|200px]]
-'''Glutathione synthetase''' (GSS) is an homo-dimeric, ATP-depending <scene name='56/564047/Biological_assembly/2'>ligase</scene> responsible for the condensation of γ-Glutamylcysteine and glycine to form Glutathione (GSH) during the second step of the glutathione biosynthesis pathway. Glutathione considered to be one of the most abundant and important antioxidants present in a wide range of cells - including bacterial, plant, and mammalian cells. In addition to protecting cells from the oxidative damage caused by free radicals, it is believed to be involved in the detoxification of xenobiotics, as well as membrane transport.
+'''Glutathione synthetase''' (GSS) is an homo-dimeric, ATP-depending ligase responsible for the condensation of γ-Glutamylcysteine and glycine to form Glutathione (GSH) during the second step of the glutathione biosynthesis pathway. Glutathione considered to be one of the most abundant and important antioxidants present in a wide range of cells - including bacterial, plant, and mammalian cells. In addition to protecting cells from the oxidative damage caused by free radicals, it is believed to be involved in the detoxification of xenobiotics, as well as membrane transport.
@@ Line 44: / Line 44: @@
 ===Glycine Triad===
-As stated previously, the catalytic active site of GSS is composed of the G-loop, S-loop, and A-loop. The G-loop has been termed the “<scene name='56/564047/Glycine_triad/1'>Glycine_Triad</scene>” due to the contribution of three glycine residues in this loop to the enzymatic activity of GSS – Gly369, Gly370, and Gly371. While all three residues are essential to the activity of the enzyme, kinetic experiments have shown Gly369 and Gly370 to have much more critical roles than Gly371. G369V and G370V variants were found to contain a mere 0.7% and 0.3% of the activity of the wild type GSS enzyme, respectively. G371V mutants still contained approximately 13% of the wild type activity, indicating a level of importance similar to the Asp458 residue of the A-loop. These experimental results suggest that the mechanism of activity interference lies in a decreased ligand binding and failure to close the active site once the ligand has bound.
+As stated previously, the catalytic active site of GSS is composed of the G-loop, S-loop, and A-loop. The G-loop has been termed the “<scene name='56/564047/Glycine_triad/1'>Glycine Triad</scene>” due to the contribution of three glycine residues in this loop to the enzymatic activity of GSS – Gly369, Gly370, and Gly371. While all three residues are essential to the activity of the enzyme, kinetic experiments have shown Gly369 and Gly370 to have much more critical roles than Gly371. G369V and G370V variants were found to contain a mere 0.7% and 0.3% of the activity of the wild type GSS enzyme, respectively. G371V mutants still contained approximately 13% of the wild type activity, indicating a level of importance similar to the Asp458 residue of the A-loop. These experimental results suggest that the mechanism of activity interference lies in a decreased ligand binding and failure to close the active site once the ligand has bound.