Regulation of glycine tRNA gene expression in the posterior silk glands of the silkworm Bombyx mori.

The glycine tRNA genes in silkworm Bombyx mori contain two regulatory regions upstream of the transcription start site as identified by direct transcription of 5' deletion mutants, transcription competition, gel mobility shift assays, and footprinting. A positive regulatory region is present in the immediate 5' flanking sequences of the four tRNA 1Gly clones studied. This region is essential for cell-free transcription in homologous extracts. A negative regulatory region is present farther upstream, and transcription competition experiments indicate its presence in three of the four clones examined.