Welcome to the new version of CaltechAUTHORS. Login is currently restricted to library staff. If you notice any issues, please email coda@library.caltech.edu
Published December 18, 1998 | public
Journal Article

Gene structures and properties of enzymes of the plasmid-encoded nicotine catabolism of Arthrobacter nicotinovorans


Arthrobacter nicotinovorans is a Gram-positive aerobic soil bacterium able to grow on nicotine as its sole source of carbon and nitrogen. The initial steps of nicotine catabolism are catalyzed by nicotine dehydrogenase, the l- and d-specific 6-hydroxynicotine oxidases, and ketone dehydrogenase. The genes encoding these enzymes reside on a 160 kb plasmid, pAO1. The cccDNA of this plasmid was isolated in high purity and reasonable yield. It served as template material for the construction of a λ-phage DNA library of the plasmid. The genes coding for 6-hydroxy-l-nicotine oxidase and for the subunits of the heterotrimeric ketone dehydrogenase were identified, subcloned and sequenced. The 6-hlno gene was identified as a 1278 bp open reading frame; its regulatory elements were also recognized. The derived primary structure of the monomer of apo-6-hydroxy-l-nicotine oxidase (46,264.5 Da) agrees with the data obtained by partial amino acid sequencing. 6-Hydroxy-l-nicotine oxidase and 6-hydroxy-d-nicotine oxidase were expressed in Escherichia coli and obtained in a state of high purity and crystallized. Ketone dehydrogenase (KDH) was found to be a heterotrimer with subunits of molecular mass 89,021.71, 26,778.65 and 17,638.88. The genes of KDH-A and KDH-B are juxtaposed; the A of the stop codon of KDH-A is used in the start codon of KDH-B, eliciting a frame shift. KDH-C is separated from KDH-A by 281 bp.

Additional Information

© 1998 Academic Press. Received 22 May 1998, Revised 24 August 1998, Accepted 3 September 1998. We thank Dr R. Maier (Freiburg) for his support in the use of the pulsed-field gel electrophoresis, Dr C. Menéndez (Freiburg) for providing the transposase A gene, Dr M. Moczko (Freiburg) for the translocase of outer membrane 70 probe. We are indebted to Dr Schlitz (Freiburg) for performing the gas-phase peptide sequencing. This work was supported by grants from the Deutsche Forschungsgemeinschaft, Bonn, through SFB 206 and De 113/34-1 and by Fonds der Chemischen Industrie, Frankfurt-M. Accession numbers: The DNA and derived protein sequences are deposited at the EMBL Nucleotide Sequence Database, accession numbers AJ 223391 (hlno), AJ 001136 (kdhA), AJ 001137 (kdhB) and AJ 001138 (kdhC).

Additional details

August 22, 2023
October 20, 2023