The C-terminal deletion mutant protein is expressed in iron-depleted medium. Whole-cell extracts from cap2Δ/Δ (lane 1), wild type (lanes 2 and 3), cap2-1 (lane 4), ΔC1 (lane 5), ΔC2 (lane 6), ΔC3 (lane 7), ΔC4 (lane 8), and cap2-2 (lane 9) strains were separated on 8 to 16% gradient SDS-polyacrylamide gels, transferred to nitrocellulose membranes, and probed with affinity-purified anti-Cap2 antibody. A 72-kDa nonspecific band that consistently appeared in all lanes as reported previously (9) is indicated by an asterisk.