Cloning, nucleotide sequence, and expression of the Escherichia coli gene encoding carnitine dehydratase.

Abstract

Carnitine dehydratase from Escherichia coli O44 K74 is an inducible enzyme detectable in cells grown anaerobically in the presence of L-(-)-carnitine or crotonobetaine. The purified enzyme catalyzes the dehydration of L-(-)-carnitine to crotonobetaine (H. Jung, K. Jung, and H.-P. Kleber, Biochim. Biophys. Acta 1003:270-276, 1989). The caiB gene, encoding carnitine dehydratase, was isolated by oligonucleotide screening from a genomic library of E. coli O44 K74. The caiB gene is 1,215 bp long, and it encodes a protein of 405 amino acids with a predicted M(r) of 45,074. The identity of the gene product was first assessed by its comigration in sodium dodecyl sulfate-polyacrylamide gels with the purified enzyme after overexpression in the pT7 system and by its enzymatic activity. Moreover, the N-terminal amino acid sequence of the purified protein was found to be identical to that predicted from the gene sequence. Northern (RNA) analysis showed that caiB is likely to be cotranscribed with at least one other gene. This other gene could be the gene encoding a 47-kDa protein, which was overexpressed upstream of caiB.

• Authors: K Eichler, W H Schunck, H P Kleber, M A Mandrand-Berthelot
• Journal: Journal of bacteriology (J Bacteriol) Vol. 176 Issue 10 Pg. 2970-5 (May 1994) ISSN: 0021-9193 [Print] United States
• PMID: 8188598 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• RNA, Messenger
• Recombinant Proteins
• Acyltransferases
• crotonobetainyl-CoA carnitine coenzyme A transferase
• Hydro-Lyases

Topics

• Acyltransferases
• Amino Acid Sequence
• Base Sequence
• Blotting, Northern
• Cloning, Molecular
• Escherichia coli (genetics)
• Genes, Bacterial (genetics)
• Hydro-Lyases (analysis, biosynthesis, genetics)
• Molecular Sequence Data
• RNA, Messenger (genetics)
• Recombinant Proteins (biosynthesis)
• Restriction Mapping
• Sequence Analysis
• Transcription, Genetic