Direct measurement of absolute suppressor efficiency

Abstract
A system was devised for measuring the degree of translational readthrough past a nonsense mutation which is based upon the quantitation of the 2 translation products, the suppressed polypeptide and the nonsense fragment. The absolute efficiency of 4 different amber suppressors (Su1, Su2, Su3 and Su7) was determined at 2 unique amber sites in the structural gene for the .beta. subunit of Escherichia coli RNA polymerase.