Previous Article | Next Article ![]()
Journal of Bacteriology, February 2001, p. 1168-1174, Vol. 183, No. 4
Department of Microbiology, Michigan State
University, East Lansing, Michigan 48824-1101
Received 9 June 2000/Accepted 16 November 2000
Members of the family Pasteurellaceae are classified in
part by whether or not they require an NAD supplement for growth on laboratory media. In this study, we demonstrate that this phenotype can
be determined by a single gene, nadV, whose presence allows NAD-independent growth of Haemophilus influenzae and
Actinobacillus pleuropneumoniae. This gene was cloned from
a 5.2-kb plasmid which was previously shown to be responsible for NAD
independence in Haemophilus ducreyi. When transformed into
A. pleuropneumoniae, this cloned gene allowed
NAD-independent growth on complex media and allowed the utilization of
nicotinamide in place of NAD on defined media. Sequence analysis
revealed an open reading frame of 1,482 bp that is predicted to encode
a protein with a molecular mass of 55,619 Da. Compared with the
sequence databases, NadV was found to have significant sequence
homology to the human pre-B-cell colony-enhancing factor PBEF and to
predicted proteins of unknown function identified in the bacterial
species Mycoplasma genitalium, Mycoplasma pneumoniae, Shewanella
putrefaciens, Synechocystis sp., Deinococcus radiodurans, Pasteurella
multocida, and Actinobacillus actinomycetemcomitans. P. multocida and A. actinomycetemcomitans are among the
NAD-independent members of the Pasteurellaceae. Homologues
of NadV were not found in the sequenced genome of H. influenzae, an NAD-dependent member of the
Pasteurellaceae, or in species known to utilize a different
pathway for synthesis of NAD, such as Escherichia coli.
Sequence alignment of these nine homologues revealed regions and
residues of complete conservation that may be directly involved in the
enzymatic activity. Identification of a function for this gene in the
Pasteurellaceae should help to elucidate the role of its
homologues in other species.
0021-9193/01/$04.00+0 DOI: 10.1128/JB.183.4.1168-1174.2001
Copyright © 2001, American Society for Microbiology. All rights reserved.
Identification of a Plasmid-Encoded Gene from
Haemophilus ducreyi Which Confers NAD Independence
*
Corresponding author. Mailing address: Department of
Microbiology, Michigan State University, East Lansing, MI 48824-1101. Phone: (517) 355-6515. Fax: (517) 353-8957. E-mail:
mulks{at}pilot.msu.edu.
This article has been cited by other articles:
| Appl. Environ. Microbiol. | Infect. Immun. | Eukaryot. Cell |
|---|---|---|
| Mol. Cell. Biol. | J. Virol. | Microbiol. Mol. Biol. Rev. |
| ALL ASM JOURNALS |