2ND-SITE REVERSION ANALYSIS IS NOT A RELIABLE METHOD TO DETERMINE DISTANCES IN MEMBRANE-PROTEINS - AN ASSESSMENT USING MUTATIONS IN YEAST CYTOCHROME-C-OXIDASE SUBUNIT-I AND SUBUNIT-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 Angstrom from the primary mutations. However, the reversions are not randomly located in the structure but reveal regions essential fo r assembly or functional units. (C) 1998 Academic Press.