1dih
THREE-DIMENSIONAL STRUCTURE OF E. COLI DIHYDRODIPICOLINATE REDUCTASE
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OverviewOverview
Dihydrodipicolinate reductase is an enzyme found in bacteria and higher, plants involved in the biosynthesis of diaminopimelic acid and lysine., Because these pathways are unique to bacteria and plants, they may, represent attractive targets for new antimicrobial or herbicidal, compounds. The three-dimensional structure of Escherichia coli, dihydrodipicolinate reductase, complexed with NADPH, has been determined, and refined to a crystallographic R-factor of 18.6% with diffraction data, to 2.2 A resolution. The refined model contains the complete protein, chain, the cofactor NADPH, and 55 water molecules. The enzyme is composed, of two domains. The dinucleotide binding domain has a central, seven-stranded parallel beta-sheet surrounded by four alpha-helices, with, the cofactor binding site located at the carboxy-terminal edge of the, sheet. The second domain contains four beta-strands and two alpha-helices, that form an open mixed beta-sandwich. A possible binding site for, dihydrodipicolinate has been identified in this second domain, about 12 A, away from the dinucleotide binding site. This would imply that the protein, must undergo some conformational change in order to perform catalysis. In, the crystal, the native enzyme is a homotetramer generated by a 222, crystallographic axis. Implications of the tetrameric structure for the, enzyme function are presented. Dihydrodipicolinate reductase uses both, NADH and NADPH as cofactors, and analysis of its cofactor binding site, allows for a molecular understanding of the enzyme's dual specificity.
About this StructureAbout this Structure
1DIH is a Single protein structure of sequence from Escherichia coli with NDP as ligand. Active as Dihydrodipicolinate reductase, with EC number 1.3.1.26 Full crystallographic information is available from OCA.
ReferenceReference
Three-dimensional structure of Escherichia coli dihydrodipicolinate reductase., Scapin G, Blanchard JS, Sacchettini JC, Biochemistry. 1995 Mar 21;34(11):3502-12. PMID:7893645
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