title: Portable Shine-Dalgarno regions: a system for a systematic study of defined alterations of nucleotide sequences within E. coli ribosome binding sites.
abstract: We have developed a gene expression system in Escherichia coli that contains a portable Shine-Dalgarno region. Transcription of this system is under the direction of a hybrid promoter (tacII) derived from trp and lac-UV5 promoter sequences which is followed by a region that encodes a portable Shine-Dalgarno region (PSDR). Using a series of synthetic PSDRs, we varied the four bases that follow the Shine-Dalgarno (SD) region. We found that the presence of four A residues or four T residues in this position gives the highest translational efficiency. The presence of four C residues reduces the translation efficiency by 50% as compared with PSDRs with A or T residues. The presence of four G residues following the SD region lowers the translational efficiency by at least 75% with respect to PSDRs with A or T residues.
mesh_terms: D001483:Base Sequence; D004269:DNA, Bacterial / Q000235:genetics*; D004926:Escherichia coli / Q000235:genetics*; D005786:Gene Expression Regulation; D009876:Operon; D010957:Plasmids; D014176:Protein Biosynthesis; D012270:Ribosomes / Q000378:metabolism; D014158:Transcription, Genetic
chemical_list: D004269:DNA, Bacterial