XVI International Botanical Congess

To investigate the transcriptional apparatus in wheat mitochondria, mitochondrial extracts were subjected to column chromatography and the resulting protein fractions were analyzed by in vitro transcription and gel mobility shift assays. This procedure yielded a 63-kDa protein (p63) that stimulates transcription in vitro. Within the predicted amino acid sequence of the p63 are blocks displaying limited similarity to positionally equivalent regions in bacterial sigma factors. Recombinant p63 possesses promoter-specific DNA-binding activity and having the ability to enhance specific transcription in vitro. These data suggest a role for p63 in transcription in wheat mitochondria.