Succinyl-CoA synthetase: Difference between revisions
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==Mechanism== | ==Mechanism== | ||
The histidine residue involved in the (de)phosphorylation of (ATP)ADP acts through the following mechanism. | |||
[[Image:Example.jpg]] | |||
A cooperative binding catalysis mechanism has been proposed and it has been shown that binding of ATP at one catalytic site promotes catalytic activity at another catalysis site.<ref>PMID:6997289</ref> It has been shown that the enzyme will bind with ATP in the presence of Mg+2 to form a complex containing 2 ATP residues as well as 2 phosphoric acid residues, after incubation this the complex converts to another one containing 4 phosphoric residues per protein. Only the second complex reacts with succinate and CoA to form the succinyl-CoA complex which then releases as many phosphoric residues as bound succinate.<ref>PMID:570066</ref> A transfer of the phosphoric residue from the first active site is seen to be coordinate with a transfer of a phosphoric residue to the second active site suggesting again a cooperative binding catalysis. This cooperative catalysis means that the presence of ATP or ADP can be both activating and inhibiting depending on the stage of catalysis they interact with the enzyme. | A cooperative binding catalysis mechanism has been proposed and it has been shown that binding of ATP at one catalytic site promotes catalytic activity at another catalysis site.<ref>PMID:6997289</ref> It has been shown that the enzyme will bind with ATP in the presence of Mg+2 to form a complex containing 2 ATP residues as well as 2 phosphoric acid residues, after incubation this the complex converts to another one containing 4 phosphoric residues per protein. Only the second complex reacts with succinate and CoA to form the succinyl-CoA complex which then releases as many phosphoric residues as bound succinate.<ref>PMID:570066</ref> A transfer of the phosphoric residue from the first active site is seen to be coordinate with a transfer of a phosphoric residue to the second active site suggesting again a cooperative binding catalysis. This cooperative catalysis means that the presence of ATP or ADP can be both activating and inhibiting depending on the stage of catalysis they interact with the enzyme. | ||