8GK8

R21A Staphylococcus aureus pyruvate carboxylase

Summary for 8GK8

• Entry DOI: 10.2210/pdb8gk8/pdb
• Descriptor: Pyruvate carboxylase, 5-(HEXAHYDRO-2-OXO-1H-THIENO[3,4-D]IMIDAZOL-6-YL)PENTANAL, COENZYME A, ... (6 entities in total)
• Functional Keywords: biotin dependent ligase, ligase
• Biological source: Staphylococcus aureus
• Total number of polymer chains: 4
• Total formula weight: 517603.94

Authors

Laseke, A.J.,St.Maurice, M. (deposition date: 2023-03-17, release date: 2023-08-30, Last modification date: 2024-03-13)

Primary citation

Laseke, A.J.,Boram, T.J.,Schneider, N.O.,Lohman, J.R.,St Maurice, M.
Allosteric Site at the Biotin Carboxylase Dimer Interface Mediates Activation and Inhibition in Staphylococcus aureus Pyruvate Carboxylase.
Biochemistry, 62:2632-2644, 2023

PubMed Abstract: Allosteric regulation of the essential anaplerotic enzyme, pyruvate carboxylase (PC), is vital for metabolic homeostasis. PC catalyzes the bicarbonate- and ATP-dependent carboxylation of pyruvate to form oxaloacetate. Dysregulation of PC activity can impact glucose and redox metabolism, which contributes to the pathogenicity of many diseases. To maintain homeostasis, PC is allosterically activated by acetyl-CoA and allosterically inhibited by l-aspartate. In this study, we further characterize the molecular basis of allosteric regulation in PC (PC) using slowly/nonhydrolyzable dethia analogues of acetyl-CoA and site-directed mutagenesis of residues at the biotin carboxylase homodimer interface. The dethia analogues fully activate PC but demonstrate significantly reduced binding affinities relative to acetyl-CoA. Residues Arg, Lys, and Glu of PC are located at the biotin carboxylase dimer interface and play a critical role in both allosteric activation and inhibition. A structure of R21A PC in complex with acetyl-CoA reveals an intact molecule of acetyl-CoA bound at the allosteric site, offering new molecular insights into the acetyl-CoA binding site. This study demonstrates that the biotin carboxylase domain dimer interface is a critical allosteric site in PC, serving as a convergence point for allosteric activation by acetyl-CoA and inhibition by l-aspartate.

PubMed: 37603581
DOI: 10.1021/acs.biochem.3c00280

Experimental method

X-RAY DIFFRACTION (2.68 Å)