Novel Binding Motif and New Flexibility Revealed by Structural Analyses of a Pyruvate Dehydrogenase-Dihydrolipoyl Acetyltransferase Subcomplex from the Escherichia coli Pyruvate Dehydrogenase Multienzyme Complex

Abstract

Background: The E. coli pyruvate dehydrogenase complex containing E1p, E2p, and E3 components converts pyruvate to acetyl-CoA. Results: The E1p-E2p subcomplex revealed a novel binding motif relative to the only other known example. Conclusion:Tethering of E1p to E2p depends on the ␣ 2 or ␣ 2 ␤ 2 assembly of E1p. Significance: The new tethering mode should affect overall complex assembly in all such complexes from Gram-negative bacteria.

Altered acetylation and succinylation profiles in Corynebacterium glutamicum in response to conditions inducing glutamate overproduction

“…It has been reported that basic residues (R and K) in the PSBD are involved in the formation of salt bridges with surface acidic residues of the N‐terminal domain (αh1‐αh2) of the E1p component (Arjunan et al. , ). We thus speculate that acylation on the three lysine residues in the PSBD may affect the binding of E1p, E1o, and/or E3 to the E2 component.…”

Phosphoproteomic analysis of bacillus Calmette–Guérin using gel-based and gel-free approaches

“…The oxidative decarboxylation of pyruvate is an important reaction in bacteria, generating acetyl-CoA, which is necessary for reactions involved in the TCA cycle and fatty acid biosynthesis. In M. tuberculosis [53] and E. coli [54], this reaction is catalyzed by the pyruvate dehydrogenase multi-enzyme complex (including DLAT). Here two phosphorylated peptides were identified in DLAT.…”

In vitro reconstitution and characterization of pyruvate dehydrogenase and 2‐oxoglutarate dehydrogenase hybrid complex from Corynebacterium glutamicum

“…As mentioned above, in E . coli , E1p and E1o utilize different sites (PSBD and the core, respectively) to bind to the cognate E2 (Packman & Perham, 1986; Frank et al, 2007; Arjunan et al, 2014), and Cg E1p and Cg E1o would not compete for binding to Cg E2. Both Cg E1p and Cg E1o utilize lipoyl residues on Cg E2 for tethering the acetyl and succinyl group derived from pyruvate and 2‐oxoglutarate, respectively.…”

“…This evidence is consistent with the formation of the PDH-ODH hybrid complex, as suggested previously (Hoffelder et al, 2010;Niebisch et al, 2006), in which both CgE1p and CgE1o subunits associate with the single CgE2-E3 subcomplex. As mentioned above, in E. coli, E1p and E1o utilize different sites (PSBD and the core, respectively) to bind to the cognate E2 (Packman & Perham, 1986;Frank et al, 2007;Arjunan et al, 2014), and CgE1p and CgE1o would not compete for binding…”