2bp7
From Proteopedia
New crystal form of the Pseudomonas putida branched-chain dehydrogenase (E1)
Structural highlights
FunctionODBA_PSEPU The branched-chain alpha-keto dehydrogenase complex catalyzes the overall conversion of alpha-keto acids to acyl-CoA and CO(2). It contains multiple copies of three enzymatic components: branched-chain alpha-keto acid decarboxylase (E1), lipoamide acyltransferase (E2) and lipoamide dehydrogenase (E3). 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 PubMedThe pyruvate dehydrogenase (PDH) multienzyme complex is central to oxidative metabolism. We present the first crystal structure of a complex between pyruvate decarboxylase (E1) and the peripheral subunit binding domain (PSBD) of the dihydrolipoyl acetyltransferase (E2). The interface is dominated by a "charge zipper" of networked salt bridges. Remarkably, the PSBD uses essentially the same zipper to alternately recognize the dihydrolipoyl dehydrogenase (E3) component of the PDH assembly. The PSBD achieves this dual recognition largely through the addition of a network of interfacial water molecules unique to the E1-PSBD complex. These structural comparisons illuminate our observations that the formation of this water-rich E1-E2 interface is largely enthalpy driven, whereas that of the E3-PSBD complex (from which water is excluded) is entropy driven. Interfacial water molecules thus diversify surface complementarity and contribute to avidity, enthalpically. Additionally, the E1-PSBD structure provides insight into the organization and active site coupling within the approximately 9 MDa PDH complex. The molecular origins of specificity in the assembly of a multienzyme complex.,Frank RA, Pratap JV, Pei XY, Perham RN, Luisi BF Structure. 2005 Aug;13(8):1119-30. PMID:16084384[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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