FUNCTION: THE ELECTRON TRANSFER FLAVOPROTEIN SERVES AS A SPECIFIC ELECTRON ACCEPTOR FOR SEVERAL DEHYDROGENASES, INCLUDING FIVE ACYL-COA DEHYDROGENASES, GLUTARYL-COA AND SARCOSINE DEHYDROGENASE. IT TRANSFERS THE ELECTRONS TO THE MAIN MITOCHONDRIAL RESPIRATORY CHAIN VIA ETF-UBIQUINONE OXIDOREDUCTASE (ETF DEHYDROGENASE). * COFACTOR: CONTAINS ONE MOLECULE OF FAD PER DIMER. * SUBUNIT: Heterodimer of an alpha and a beta subunit. * SUBCELLULAR LOCATION: Mitochondrial matrix. * TISSUE SPECIFICITY: ABUNDANT IN LIVER, HEART AND SKELETAL MUSCLE. A WEAK EXPRESSION IS SEEN IN THE BRAIN, PLACENTA, LUNG, KIDNEY AND PANCREAS. * DISEASE: DEFECTS IN ETFB ARE THE CAUSE OF GLUTARIC ACIDURIA TYPE IIB (GAIIB) (GLUTARICACIDURIA) WHICH RESULTS IN THE EXCRETION NOT ONLY OF GLUTARIC ACID BUT ALSO OF LACTIC, ETHYLMALONIC, BUTYRIC, ISOBUTYRIC, 2-METHYL-BUTYRIC, AND ISOVALERIC ACIDS. IT IS SEEN IN ITS MOST SEVERE FORM IN INFANCY, WITH POLYCYSTIC AND DYSPLASTIC KIDNEYS, HYPOKETOTIC ACIDOSIS AND HYPOGLYCEMIA THAT CAN LEAD TO DEATH. THE MILDER FORM CAN BE CHARACTERIZED BY RECURRENT EPISODES OF LASTING LETHARGY OR SLOWLY PROGRESSIVE MYOPATHY. * SIMILARITY: BELONGS TO THE ETF BETA-SUBUNIT / FIXA FAMILY. |
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25-JAN-03
Last Update 13-Mar-03