Rescuing a cryptic translation initiation site in ALA1. (A) Complementation assays for mitochondrial AlaRS activity. (B) Assay of initiating activity by Western blots. Upper panel, AlaRS-LexA fusion; lower panel, PGK (as loading controls). (C) RT-PCR. Relative amounts of specific ALA1-lexA mRNAs generated from each construct were determined by RT-PCR. As a control, relative amounts of actin mRNAs were also determined. The ALA1 sequences used in the ALA1-lexA constructs 1~4 in (B) were respectively transferred from constructs 1~4 shown in (A). In (C) the numbers 1~4 (circled) denote constructs shown in (B).