Part:BBa_K4989005

Electron transfer protein alpha subunit (Etfa)

The gene efb encodes for the electron transfer flavoprotein subunit alpha, which creates the heterodimeric electron transfer flavoprotein (ETF), when it is joined by the electron transfer flavoprotein subunit beta. Those subunits are the fifth and sixth enzymes that are involved in the butyrate-producing metabolic pathway. Both subunits have orthologs in mammalian cells, which exist in the mitochondria and are included in various reactions. The α subunit is a precursor protein in the mitochondria, while the β subunit is expressed in the cytosol and is transferred into the mitochondria. The ETF protein is involved in electron burification which is a mechanism to couple endergonic to exergonic redox reactions widely distributed in anaerpbic bacteria. ETF creates a complex with butyryl-CoA dehydrogenase (BCD), a so-called ETF-BCD complex which was the first to be studied. This complex couples the exergonic reaction of crotonyl-CoA to butyryl-CoA by NADH with the endergonic reaction of ferredoxin. Current understanding indicates that the electron pair of NADH is split at the two-electron acceptor and one-electron donor FAD; one electron decreases the dehydrogenase FAD of Bcd and the other goes to ferredoxin (Fd), which has a low redox potential (E0′ = 405 mV). When this process is repeated, hydrogen transfer from FADH of Bcd to crotonyl-CoA results in a second decreased ferredoxin and butyryl-CoA. Two subunits make up the Etf complex from Acidaminococcus fermentans, according to structural and biochemical analyses. The α subunit coordinates one flavin adenine dinucleotide (FAD) (α-FAD), while the β subunit coordinates a second FAD (-FAD). Because NADH binds near this cofactor, the β-FAD was determined to be the location of hydride acceptance from NADH and electron bifurcation.

Sequence and Features

Assembly Compatibility:

• 10
  COMPATIBLE WITH RFC[10]
• 12
  COMPATIBLE WITH RFC[12]
• 21
  COMPATIBLE WITH RFC[21]
• 23
  COMPATIBLE WITH RFC[23]
• 25
  INCOMPATIBLE WITH RFC[25]

  Illegal NgoMIV site found at 993
  Illegal AgeI site found at 349
  
• 1000
  COMPATIBLE WITH RFC[1000]