Sequencing, characterization, and gene expression analysis of the histidine decarboxylase gene cluster of Morganella morganii.
The histidine decarboxylase gene cluster of Morganella morganii DSM30146(T) was sequenced, and four open reading frames, named hdcT1, hdc, hdcT2, and hisRS were identified. Two putative histidine/histamine antiporters (hdcT1 and hdcT2) were located upstream and downstream the hdc gene, codifying a pyridoxal-P dependent histidine decarboxylase, and followed by hisRS gene encoding a histidyl-tRNA synthetase. This organization was comparable with the gene cluster of other known Gram negative bacteria, particularly with that of Klebsiella oxytoca. Recombinant Escherichia coli strains harboring plasmids carrying the M. morganii hdc gene were shown to overproduce histidine decarboxylase, after IPTG induction at 37 °C for 4 h. Quantitative RT-PCR experiments revealed the hdc and hisRS genes were highly induced under acidic and histidine-rich conditions. This work represents the first description and identification of the hdc-related genes in M. morganii. Results support the hypothesis that the histidine decarboxylation reaction in this prolific histamine producing species may play a role in acid survival. The knowledge of the role and the regulation of genes involved in histidine decarboxylation should improve the design of rational strategies to avoid toxic histamine production in foods.
Department of Food, Environmental and Nutritional Sciences (DeFENS), University of Milan, Via Celoria 2, 20133, Milan, Italy.
Chiara
C
Ferrario
Francesca
F
Borgo
Blanca
B
de Las Rivas
Rosario
R
Muñoz
Giovanni
G
Ricci
Maria Grazia
MG
Fortina
D003001:Cloning, Molecular; D004926:Escherichia coli / Q000235:genetics; D015870:Gene Expression; D020869:Gene Expression Profiling; D023061:Gene Order; D006640:Histidine Decarboxylase / Q000096:biosynthesis* / Q000235:genetics*; D041121:Klebsiella oxytoca / Q000235:genetics; D008969:Molecular Sequence Data; D020613:Morganella morganii / Q000201:enzymology* / Q000235:genetics*; D005810:Multigene Family; D016366:Open Reading Frames; D010957:Plasmids; D011994:Recombinant Proteins / Q000235:genetics; D017422:Sequence Analysis, DNA; D026801:Synteny
D011994:Recombinant Proteins; D006640:Histidine Decarboxylase