PCCA gene

propionyl-CoA carboxylase subunit alpha

The PCCA gene provides instructions for making part of an enzyme called propionyl-CoA carboxylase, specifically, the alpha subunit of this enzyme. Six alpha subunits come together with six beta subunits (produced from the PCCB gene) to form a functioning enzyme. The alpha subunit also includes a region for binding to the B vitamin biotin.

Propionyl-CoA carboxylase plays a role in the normal processing of proteins. It carries out a particular step in the breakdown of several protein building blocks (amino acids) called isoleucine, methionine, threonine, and valine. Propionyl-CoA carboxylase also helps break down certain types of lipids (fats) and cholesterol. First, several chemical reactions convert the amino acids, lipids, or cholesterol to a molecule called propionyl-CoA. Using biotin, propionyl-CoA carboxylase then converts propionyl-CoA to a molecule called methylmalonyl-CoA. Additional enzymes break down methylmalonyl-CoA into other molecules that are used for energy.

More than 120 mutations in the PCCA gene have been identified in people with propionic acidemia, a condition that causes severe health problems appearing shortly after birth. These mutations include changes in single DNA building blocks (nucleotides) and insertions or deletions of genetic material in the PCCA gene. PCCA mutations prevent the production of functional propionyl-CoA carboxylase or reduce the enzyme's activity. The altered or missing enzyme is unable to process certain parts of proteins and lipids properly. As a result, propionyl-CoA and other potentially harmful compounds can build up to toxic levels in the body. This buildup damages the brain and nervous system, causing the serious health problems associated with propionic acidemia.

Cytogenetic Location: 13q32.3, which is the long (q) arm of chromosome 13 at position 32.3

Molecular Location: base pairs 100,089,015 to 100,530,437 on chromosome 13 (Homo sapiens Updated Annotation Release 109.20200522, GRCh38.p13) (NCBI)

Cytogenetic Location: 13q32.3, which is the long (q) arm of chromosome 13 at position 32.3
  • PCCase alpha subunit
  • propionyl-CoA carboxylase alpha subunit
  • propionyl CoA carboxylase, alpha polypeptide
  • propionyl-CoA:carbon dioxide ligase alpha subunit
  • propionyl Coenzyme A carboxylase, alpha polypeptide