RESUMO

The pst operon of Escherichia coli, which encodes the phosphate-specific transport system, is composed of five genes, pstS, pstC, pstA, pstB and phoU, whose transcription is induced by phosphate starvation. A phosphate-regulated promoter located upstream of the most proximal gene ( pstS) controls the transcription of the entire operon. Though the full-length pst mRNA could be detected by an improved RT-PCR protocol, Northern analysis using several pst-specific probes failed to reveal this transcript. Instead, smaller but distinct pst mRNA species were evident. Primer-extension experiments localized the 5' ends of pst mRNAs within the operon. The data suggest that the full-length mRNA is rapidly processed post-transcriptionally.

Assuntos

Transportadores de Cassetes de Ligação de ATP/genética , Proteínas de Bactérias/genética , Escherichia coli/genética , Óperon/genética , Transcrição Gênica , Fosfatase Alcalina/metabolismo , Northern Blotting , Primers do DNA/química , Família Multigênica/genética , Fosfatos/metabolismo , Regiões Promotoras Genéticas , RNA Mensageiro/análise , Reação em Cadeia da Polimerase Via Transcriptase Reversa