1qjc

From Proteopedia

PHOSPHOPANTETHEINE ADENYLYLTRANSFERASE IN COMPLEX WITH AMPCPP AND 4'-PHOSPHOPANTETHEINE FROM ESCHERICHIA COLI

Overview

Phosphopantetheine adenylyltransferase (PPAT) is an essential enzyme in, the coenzyme A pathway that catalyzes the reversible transfer of an, adenylyl group from ATP to 4'-phosphopantetheine (Ppant) in the presence, of magnesium. To investigate the reaction mechanism, the high-resolution, crystal structures of the Escherichia coli PPAT have been determined in, the presence of either ATP or Ppant. Structural details of the catalytic, center revealed specific roles for individual amino acid residues involved, in substrate binding and catalysis. The side-chain of His18 stabilizes the, expected pentacovalent intermediate, whereas the side-chains of Thr10 and, Lys42 orient the nucleophile for an in-line displacement mechanism. The, binding site for the manganese ion that interacts with the phosphate, groups of the nucleotide has also been identified. Within the PPAT, hexamer, one trimer is in its substrate-free state, whereas the other is, in a substrate-bound state.

About this Structure

1QJC is a Single protein structure of sequence from Escherichia coli with SO4 and PNS as ligands. Active as Pantetheine-phosphate adenylyltransferase, with EC number 2.7.7.3 Known structural/functional Site: . Full crystallographic information is available from OCA.

Reference

The crystal structures of phosphopantetheine adenylyltransferase with bound substrates reveal the enzyme's catalytic mechanism., Izard T, J Mol Biol. 2002 Jan 25;315(4):487-95. PMID:11812124

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