Disease relevance of trpL

• By connecting the PL promoter of lambda phage, the SD sequence of trpL of E. coli, and ATG, at a suitable position upstream of the guaA gene, we obtained plasmid pPLA66 [1].
• It was previously reported that transcription of the Rhizobium meliloti trpE(G) gene starts at the adenine residue of the AUG codon of the leader peptide coding sequence (trpL), suggesting that translation of the trpL sequence starts without the Shine-Dalgarno sequence [2].
• In pIK75, the start ATG was placed 16 bp downstream of the trpL Shine-Dalgarno sequence under the control of the E. coli trp promoter [3].

High impact information on trpL

• Sequential deletion of trpL DNA specifying the leader peptide initiation region, RNA segment 1, RNA segment 2 and RNA segment 3 alternately decreased and increased trp operon expression, a result consistent with previous findings in another bacterium and the generally accepted model for transcription attenuation [4].
• In addition, these mutations, as well as a mutation converting the eighth codon (UCG) of the trpL sequence to UGA, abolished regulation by attenuation when introduced upstream of the tandem tryptophan codons in a trpE'-'lacZ fusion [2].
• These mutations reduced the expression of a trpL'-'lacZ fusion gene to 0.1 and 0.2% of the wild-type level, respectively, indicating that the AUG codon is the translation initiation codon for the trpL coding sequence [2].
• The 5'-flanking region encodes two open reading frames (ORFs); one corresponds to trpL, while the other corresponds to the N-terminal half of the trpE gene [5].
• A similar plasmid, pCR601, which contains the same coding sequence fused to the trp promoter and N-terminal fragment of the trpL gene, directs the production of PC at the same rate as pCR501 [6].

Associations of trpL with chemical compounds

• Within the 17 amino acid residues of the predicted leader peptide encoded by trpL are found three contiguous tryptophan residues [5].

References