Sequence analysis of the inducible chloramphenicol resistance determinant in the Tn1696 integron suggests regulation by translational attenuation.
The sequence of the Tn1696 determinant for inducible nonenzymatic chloramphenicol resistance has been determined. The cml region, the fourth insert of the Tn1696 integron, is 1547 bases and includes a 59-base element at the 3' end, as is typical of integron inserts. One gene, designated cmlA and predicting a polypeptide of 44.2 kDa, is encoded in the insert. However, the cmlA region shows one feature not previously found in an integron insert. A promoter is located within the cmlA insert, and translational attenuation signals related to those of the inducible cat and ermC genes found in gram-positive organisms are also present. The regulatory region includes a leader peptide of nine amino acids, a ribosome stall sequence related to those preceding cat genes, and two alternative pairs of stem-loop structures which either sequester or disclose the ribosome binding site and start codon preceding the cmlA gene.
Stokes
H W
HW
School of Biological Sciences, Macquarie University, Sydney, NSW, Australia.
Hall
R M
RM
D000595:Amino Acid Sequence; D001483:Base Sequence; D002701:Chloramphenicol / Q000494:pharmacology*; D003001:Cloning, Molecular; D004251:DNA Transposable Elements; D004269:DNA, Bacterial / Q000235:genetics / Q000302:isolation & purification; D004352:Drug Resistance, Microbial / Q000235:genetics*; D004926:Escherichia coli / Q000235:genetics*; D015964:Gene Expression Regulation, Bacterial; D005798:Genes, Bacterial; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D010957:Plasmids; D014176:Protein Biosynthesis; D021382:Protein Sorting Signals / Q000235:genetics; D012333:RNA, Messenger / Q000235:genetics; D015183:Restriction Mapping; D012689:Sequence Homology, Nucleic Acid
D004251:DNA Transposable Elements; D004269:DNA, Bacterial; D021382:Protein Sorting Signals; D012333:RNA, Messenger; D002701:Chloramphenicol