This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Reprints and Permissions Copyright Information Books from ASM Press MicrobeWorld Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Schaferkordt, S. Articles by Chakraborty, T. Search for Related Content PubMed PubMed Citation Articles by Schaferkordt, S. Articles by Chakraborty, T.

 Previous Article  |  Next Article 

J. Bacteriol., Apr 1997, 2707-2716, Vol 179, No. 8
Copyright © 1997, American Society for Microbiology

Identification, cloning, and characterization of the Ima operon, whose gene products are unique to Listeria monocytogenes

S Schaferkordt and T Chakraborty
Institut fur Medizinische Mikrobiologie, Justus-Leibig Universitat Giessen, Germany.

The lmaA gene of Listeria monocytogenes encodes a protein capable of inducing delayed-type hypersensitivity reactions in L. monocytogenes- immune mice (S. Gohmann, M. Leimeister-Wachter, E. Schiltz, W. Goebel, and T. Chakraborty, M. Microbiol. 4:1091-1099, 1990). Here we show that it is the last gene of the lma operon, which now comprises four genes, lmaDCBA. Maxicell analysis of peptides encoded by the lma operon identified four polypeptides of 16.7, 16.4, 14.9, and 21 kDa which correspond to the gene products encoded by the lmaD, -C, -B, and -A genes, respectively. Northern blot analysis of the lma operon showed that lmaA is expressed by two transcripts: the longer lmaDCBA transcript of 2,100 nucleotides, which was observed at growth temperatures of 37 and 20 degrees C, and a shorter transcript consisting of lmaBA, which is detected only at low temperatures (20 degrees C). Two promoters, one preceding the lmaD gene and another located upstream of the lmaB gene, were detected. An extended stem-loop structure resembling box elements found in other gram-positive pathogens was also present in the lmaC-lmaB intergenic region. By immunoblot analysis, we found that although LmaA was produced at both temperatures (20 and 37 degrees C), it was secreted into culture supernatants only at 20 degrees C. However, LmaA lacks a bona fide signal peptide sequence and could, like flagellin, be secreted by a type III transport system. DNA hybridization studies indicate that the lma operon is species specific and restricted to pathogenic strains of L. monocytogenes.

This article has been cited by other articles:

• Abram, F., Starr, E., Karatzas, K. A. G., Matlawska-Wasowska, K., Boyd, A., Wiedmann, M., Boor, K. J., Connally, D., O'Byrne, C. P. (2008). Identification of Components of the Sigma B Regulon in Listeria monocytogenes That Contribute to Acid and Salt Tolerance. Appl. Environ. Microbiol. 74: 6848-6858 [Abstract] [Full Text]  
• Hu, Y., Oliver, H. F., Raengpradub, S., Palmer, M. E., Orsi, R. H., Wiedmann, M., Boor, K. J. (2007). Transcriptomic and Phenotypic Analyses Suggest a Network between the Transcriptional Regulators HrcA and {sigma}B in Listeria monocytogenes. Appl. Environ. Microbiol. 73: 7981-7991 [Abstract] [Full Text]  
• Chan, Y. C., Raengpradub, S., Boor, K. J., Wiedmann, M. (2007). Microarray-Based Characterization of the Listeria monocytogenes Cold Regulon in Log- and Stationary-Phase Cells. Appl. Environ. Microbiol. 73: 6484-6498 [Abstract] [Full Text]  
• Roberts, A., Nightingale, K., Jeffers, G., Fortes, E., Kongo, J. M., Wiedmann, M. (2006). Genetic and phenotypic characterization of Listeria monocytogenes lineage III.. Microbiology 152: 685-693 [Abstract] [Full Text]  
• Johnson, J., Jinneman, K., Stelma, G., Smith, B. G., Lye, D., Messer, J., Ulaszek, J., Evsen, L., Gendel, S., Bennett, R. W., Swaminathan, B., Pruckler, J., Steigerwalt, A., Kathariou, S., Yildirim, S., Volokhov, D., Rasooly, A., Chizhikov, V., Wiedmann, M., Fortes, E., Duvall, R. E., Hitchins, A. D. (2004). Natural Atypical Listeria innocua Strains with Listeria monocytogenes Pathogenicity Island 1 Genes. Appl. Environ. Microbiol. 70: 4256-4266 [Abstract] [Full Text]  
• Arous, S., Buchrieser, C., Folio, P., Glaser, P., Namane, A., Hebraud, M., Hechard, Y. (2004). Global analysis of gene expression in an rpoN mutant of Listeria monocytogenes. Microbiology 150: 1581-1590 [Abstract] [Full Text]  
• Lang, A. S., Beatty, J. T. (2000). Genetic analysis of a bacterial genetic exchange element: The gene transfer agent of Rhodobacter capsulatus. Proc. Natl. Acad. Sci. USA 97: 859-864 [Abstract] [Full Text]