SDHC

Succinate dehydrogenase complex subunit A (SDHA) is a protein that in humans is encoded by the SDHA gene. SDHA is a component of the succinate dehydrogenase (SDH) complex, also known as complex II, which is part of both the citric acid cycle and the electron transport chain in mitochondria.

Structure

SDHA is the largest subunit of the succinate dehydrogenase complex and contains the flavin adenine dinucleotide (FAD) cofactor. The SDHA protein is composed of 664 amino acids and has a molecular weight of approximately 72 kDa. The structure of SDHA allows it to catalyze the oxidation of succinate to fumarate, a key step in the citric acid cycle.

Function

SDHA plays a crucial role in cellular energy metabolism. It is responsible for the oxidation of succinate to fumarate in the citric acid cycle, a process that generates FADH2, which subsequently donates electrons to the electron transport chain. This electron transfer is essential for the production of ATP through oxidative phosphorylation.

Clinical Significance

Mutations in the SDHA gene can lead to a variety of medical conditions, including mitochondrial complex II deficiency, which can result in a range of symptoms from muscle weakness to neurological disorders. SDHA mutations have also been associated with certain types of paragangliomas and pheochromocytomas, which are tumors that arise from the sympathetic nervous system.

Research and Implications

Research into SDHA and its associated pathways is ongoing, with implications for understanding metabolic diseases, cancer, and aging. The role of SDHA in reactive oxygen species (ROS) production and its potential involvement in apoptosis are areas of active investigation.

Also see

• Citric acid cycle
• Electron transport chain
• Mitochondrial diseases
• Paraganglioma
• Pheochromocytoma