(D) Sucrose density gradient sedimentation profile ("long gradients" as in figure 4D) of ERAL1, MRPS35, MRPL37, CLPX and EFG1 from control (Clpp+/+) and Clpp knockout (Clpp-/-) heartmitochondria. The same amount of protein lysates were separated by the gradient and the amount of each individual protein is estimated after Western blot analysis (Input). Only fractions 4 - 11 containing the 28S, 39S and 55S ribosomal fractions were blotted to avoid high signals arising in free fractions (1-3). 