Second-site reversion analysis is not a reliable method to determine distances in membrane proteins: an assessment using mutations in yeast cytochrome c oxidase subunits I and II.

We have examined deficiency mutations and reversions in subunits I and II of yeast cytochrome c oxidase in order to test the reliability of second-site reversion analysis in prediction of tertiary structure of a membrane protein complex. It appears that the method can not provide information on distance between residues, since reversions can be up to 30 A from the primary mutations. However, the reversions are not randomly located in the structure but reveal regions essential for assembly or functional units. Copyright 1998 Academic Press.