FIG. 7.

Iba57p interacts with Isa1p and Isa2p. (A) Cell extracts were prepared from W303-1A and iba57Δ strains grown overnight in YP glucose and immunostained for Isa1p and Isa2p. α-Tubulin (Serotec) served as a loading control. (B) W303-1A WT, depleted Gal-IBA57, and iba57Δ strains were transformed with p426-ISA2 and grown overnight in iron-depleted glucose minimal medium, and ⁵⁵Fe binding to Isa2p was analyzed by radiolabeling and immunoprecipitation as described in Fig. 3. Leu1p and Mge1p were detected with polyclonal antisera. (C) Mitochondria from WT cells and galactose-induced Gal-IBA57-Myc cells with or without overproduced Isa2p were lysed by detergent, and immunoprecipitations were carried out with antibodies to Isa2p and the Myc tag. The purified immunobeads were analyzed for the presence of Iba57p-Myc and Isa2p by immunostaining. (D) Mitochondria from WT, Gal-IBA57-Myc cells with or without overproduced Isa1p were lysed by detergent, and immunoprecipitations were carried out with antibodies to Isa1p and Myc. The purified immunobeads were analyzed by immunostaining.