Regulation of Yersinia enterocolitica mal genes by MalT and Mlc proteins.
To show the role of MalT protein in the regulation of mal genes, encoding proteins involved in transport and metabolism of maltose/ maltodextrins in Yersinia enterocolitica, we constructed a malT mutant which was characterized by a strong reduction in maltose transport and a loss of MBP protein. We also studied the influence of MalT activity on the production of Yop proteins in Y. enterocolitica and found that the level of these virulence factors is not changed in the malT mutant. Subsequently, transcriptional fusion malT::lacZYA was applied to study the activity of malT promoter. Monitoring of beta-galactosidase activity suggests the influence of catabolic repression on malT transcription, sincethe activity of malT promoter was decreased twofold in the presence of glucose. Furthermore, Mlc protein was identified in Y. enterocolitica as a factor regulating the transcription of malT. We observed a two-fold increase in the level of malT transcription in the mlc mutant background. Moreover, overproduction of Mlc protein strongly inhibited the activity of malT promoter. Thus, the data presented in this study suggest that the level of mal gene expression in Y. enterocolitica may be regulated by two proteins: MalT, the activator of mal transcription and Mlc, the repressor of malT expression.
Raczkowska
Adrianna
A
Department of Applied Microbiology, Institute of Microbiology, Faculty of Biology, University of Warsaw, Warszawa, Poland. araczko@biol.uw.edu.pl
Brzóstkowska
Marta
M
Brzostek
Katarzyna
K
D000595:Amino Acid Sequence; D002352:Carrier Proteins / Q000378:metabolism; D003001:Cloning, Molecular; D003227:Conjugation, Genetic; D015964:Gene Expression Regulation, Bacterial; D005798:Genes, Bacterial; D005816:Genetic Complementation Test; D005947:Glucose / Q000378:metabolism; D008320:Maltose / Q000378:metabolism*; D058619:Maltose-Binding Proteins; D008969:Molecular Sequence Data; D016254:Mutagenesis, Insertional; D033902:Periplasmic Binding Proteins / Q000378:metabolism; D010957:Plasmids; D011401:Promoter Regions, Genetic; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D012097:Repressor Proteins / Q000378:metabolism*; D014158:Transcription, Genetic; D037521:Virulence Factors / Q000378:metabolism; D015008:Yersinia enterocolitica / Q000235:genetics* / Q000302:isolation & purification / Q000472:pathogenicity
D002352:Carrier Proteins; D058619:Maltose-Binding Proteins; D033902:Periplasmic Binding Proteins; D011993:Recombinant Fusion Proteins; D012097:Repressor Proteins; D037521:Virulence Factors; D008320:Maltose; D005947:Glucose