Topogenesis of cytochrome P450scc, a resident proteinof the inner membrane of adrenocortical mitochondria, is still obscure. In particular, little is known about the cause of its tissue specificity. In an attempt to clarify this point, we examined the process in Saccharomyces cerevisiae cells synthesizing cytochrome P450scc as its native precursor (pCYP11A1) or versions inwhich its N-terminal addressing presequence had been replaced with those of yeast mitoch-ondrial proteins: CoxIV(1–25) and Su9(1–112)
