1u7u
From Proteopedia
Phosphopantothenoylcysteine synthetase from E. coli
Structural highlights
Function[COABC_ECOLI] Catalyzes two steps in the biosynthesis of coenzyme A. In the first step cysteine is conjugated to 4'-phosphopantothenate to form 4-phosphopantothenoylcysteine, in the latter compound is decarboxylated to form 4'-phosphopantotheine. Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedPhosphopantothenoylcysteine (PPC) synthetase forms a peptide bond between 4'-phosphopantothenate and cysteine in coenzyme A biosynthesis. PPC synthetases fall into two classes: eukaryotic, ATP-dependent and eubacterial, CTP-dependent enzymes. We describe the first crystal structure of E. coli PPC synthetase as a prototype of bacterial, CTP-dependent PPC synthetases. Structures of the apo-form and the synthetase complexed with CTP, the activated acyl-intermediate, 4'-phosphopantothenoyl-CMP, and with the reaction product CMP provide snapshots along the reaction pathway and detailed insight into substrate binding and the reaction mechanism of peptide bond formation. Binding of the phosphopantothenate moiety of the acyl-intermediate in a cleft at the C-terminal end of the central beta sheet of the dinucleotide binding fold is accomplished by an otherwise flexible flap. A second disordered loop may control access of cysteine to the active site. The conservation of functionalities involved in substrate binding and catalysis provides insight into similarities and differences of prokaryotic and eukaryotic PPC synthetases. Structural basis of CTP-dependent peptide bond formation in coenzyme A biosynthesis catalyzed by Escherichia coli PPC synthetase.,Stanitzek S, Augustin MA, Huber R, Kupke T, Steinbacher S Structure. 2004 Nov;12(11):1977-88. PMID:15530362[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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