In vitro transcription of normal, mutant, and truncated mouse alpha-globin genes.

Abstract
Various .alpha.-globin gene-containing templates were transcribed by using a simplified in vitro system. The 5'' end of each of the RNA polymerase II-specific transcripts corresponds to an authentic .alpha.-globin mRNA. Using a truncated .alpha.-globin gene fragment, the promoter region of the adult .alpha.-globin gene was localized to a 148-base-pair fragment of .alpha.-globin DNA, 141 nucleotides of which precede the initiation site. When 2 naturally occurring .alpha.-globin gene mutants were tested as templates, no RNA polymerase II-dependent initiation was detected. Comparison of the nucleotide sequences of the normal and mutant .alpha.-globin genes has allowed us to focus upon nucleotide positions that might be essential for promoter activity.