by using both the isolated iron-protein fraction and the intact dehydrogenase , cross-links were identified between these four subunits , from these subunits to the largest subunit of the flavoprotein fraction , which contains the active site for nadh , and from these subunits to polypeptides in the hydrophobic shell , which surrounds the hydrophilic iron-protein and flavoprotein fractions .
C0033684
protein
C0016223
flavoprotein