pyruvate carboxylase, mitochondrial (pyruvic carboxylase, PCB, PC)

Function

• gluconeogenesis & lipogenesis
• catalyzes the ATP-dependent reaction of pyruvate with CO2 to form oxaloacetate
• pyruvate carboxylase catalyzes a 2-step reaction, involving
  • ATP-dependent carboxylation of covalently attached biotin
  • transfer of the carboxyl group to pyruvate
    • catalyzes (tissue specific) initial reactions of glucose (liver, kidney) & lipid (adipose tissue, liver, brain) synthesis from pyruvate

ATP + pyruvate + HCO3- <--> ADP + phosphate + oxaloacetate

Cofactors: biotin, Mn+2

Structure

• homotetramer
• contains 1 ATP-grasp domain
• contains 1 biotin carboxylation domain
• contains 1 biotinyl-binding domain
• contains 1 carboxyltransferase domain

Compartment

mitochondrial matrix

Pathology

• defects in PC result in pyruvate carboxylase deficiency

More general terms

• carboxy-lyase or decarboxylase
• gluconeogenic enzyme
• mitochondrial protein
• phosphoprotein

Database

• OMIM: https://mirror.omim.org/entry/266150
• OMIM: https://mirror.omim.org/entry/608786
• UniProt: http://www.uniprot.org/uniprot/P11498.html