FIG. 7.

Correlation of complementing activity with a 65-kDa protein. (A) Proteins eluted from the wild-type (WT) or mutant RNA affinity columns were analyzed either directly or after UV cross-linking to labeled apo-B RNA. Untreated and UV cross-linked samples were electrophoresed in parallel on the same SDS–8% PAGE gel. One-half of the gel was silver stained, while the other half was developed by autoradiography. The position of the 65-kDa protein is indicated by an arrow. (B) Results of far-Western analysis with [³⁵S]cysteine-labeled apobec-1 as the probe. The affinity-purified proteins from the wild-type or mutant RNA columns were resolved by SDS–8% PAGE and transferred to polyvinylidene difluoride membranes as described in Materials and Methods. Proteins were subjected to multiple cycles of denaturation and renaturation and probed with [³⁵S]cysteine-labeled apobec-1.