SDHA

From Wikipedia, the free encyclopedia

succinate dehydrogenase complex, subunit A, flavoprotein (Fp)
Identifiers
Symbol SDHA SDH2
HUGO 10680
Entrez 6389
OMIM 600857
RefSeq NM_004168
UniProt Q59GW8
Other data
Locus Chr. 5 p15

SDHA is an acronym for succinate dehydrogenase complex subunit A.

The term SDHA can refer to;

  • The protein subunit itself.
  • The gene that codes for this protein.

The succinate dehydrogenase (SDH) protein complex catalyzes the oxidation of succinate (succinate + ubiquinone => fumarate + ubiquinol). The SDHA subunit is connected to the SDHB subunit on the hydrophilic, catalytic end of the complex, and weighs 72.7 kDA. Electrons removed from succinate transfer SDHA, to SDHB and further to the SDHC/SDHD subunits on the hydrophobic end of the complex anchored in the mitochondrial membrane.

[edit] Function of the SDHA Protein

The SDH complex is located on the inner membrane of the mitochondria and participates in both the Citric Acid Cycle and Respiratory chain.

SDHA acts as an intermediate in the basic SDH enzyme action:

  1. SDHA converts succinate to fumarate as part of the Citric Acid Cycle. This reaction also converts FAD to FADH2.
  2. Electrons from the FADH2 are transferred to the SDHB subunit iron clusters [2Fe-2S],[4Fe-4S],[3Fe-4S]. This function is part of the Respiratory chain
  3. Finally the electrons are transferred to the Ubiquinone (Q) pool via the SDHC/SDHD subunits.

[edit] Gene that Codes for SDHA

The gene that codes for the SDHA protein is nuclear, even though the protein is located in the inner membrane of the mitochondria. The location of the gene in humans is on the fifth chromosome at p15. The gene is partitioned in 15 exons. The expressed protein has 664 amino acids.