Salmonella typhimurium regulation

Romling U., Rohde M., Olsen A., Normark S., and Reinkoster J. 2000. AgfD, the checkpoint of multicellular and aggregative behaviour in Salmonella typhimurium regulates at least two independent pathways. Mol Microbiol 36 10-23. 

Jiang W, WW Metcalf, K-S Lee, BL Wanner (1995) Molecular cloning, mapping, and regulation of the pho regulon genes for phosphonate breakdown by the phosphonatase pathway of Salmonella typhimurium LT2. J Bacteriol 111 6411-6421. 

Romling, U., Bain, Z., Hammar, M., Sierralta, W. D., and Normark, S. (1998). Curli fibers are highly conserved between Salmonella typhimurium and Escherichia coli with respect to operon structure and regulation. /. Bacteriol. 180, 722-731. 

Hydrogenase isoenzymes are also common among the metabolically more versatile bacteria (see Chapter 2). For instance, H2 metabolism and isoenzyme composition in enteric bacteria, including Escherichia coli and Salmonella typhimurium, appear to be differentially regulated under the two modes of anaerobic life, fermentation and anaerobic respiration (Table 3.1). Furthermore, biosynthesis of the individual isoenzymes appears to be controlled at a global level by the quality of the carbon source. 

Regulation of histidine synthesis. In all, ten different genes code for the enzymes of histidine biosynthesis in Salmonella typhimurium. They are clustered as the histidine operon, a consecutive series of genes which are transcribed into messenger RNA as a unit.250 251 The gene symbols His A, HisB, etc., are indicated in Fig. 25-13, and their positions on the E. coli gene map are indicated in Fig. 26-4. The gene HisB codes for a complex protein with two different enzymatic activities as shown in Fig. 25-13. 

Higgins, C.F., Dorman, C.J., Stirling, D.A., Waddell, L., Booth, I.R., May, G. Bremer, E. (1988). A physiological role for DNA supercoiling in the osmotic regulation of gene expression in Salmonella typhimurium and Escherichia coli. Cell 52, 569-84. 

A.K. Debnath et al., Quantitative structure-activity relationship investigation of the role of hydrophobicity in regulating mutagenicity in the Ames test 2 Mutagenicity of aromatic and heteroaromatic nitro compounds in Salmonella typhimurium TA100. Environ. Mol. Mutagen. 19, 53-70 (1992)... 

Bader, M.W., Navarre, W.W., Shiau, W., Nikaido, H., Frye, J.G., McClelland, M., Fang, F.C., Miller, S.I. Regulation of Salmonella typhimurium virulence gene expression by cationic antimicrobial peptides. Mol Microbiol 50 (2003) 219-230. 

Guo, L., Lim, K.B., Gunn, J.S., Bainbridge, B., Darveau, R.P., Hackett, M., Miller, S.I. Regulation of lipid A modifications by Salmonella typhimurium virulence genes phoP-phoQ. Science 276 (1997) 250-253. 

Kawasaki, K., Ernst, R.K., Miller, S.I. 3-O-deacylation of lipid A by PagL, a PhoP/PhoQ-regulated deacylase of Salmonella typhimurium, modulates signaling through Toll-like receptor 4. J Biol Chem 279 (2004) 20044-20048. 

Soncini, F.C., Garcia Vescovi, E., Solomon, F., Groisman, E.A. Molecular basis of the magnesium deprivation response in Salmonella typhimurium. identification of PhoP-regulated genes. J Bacteriol 178 (1996) 5092-5099. 

Groisman, E., Chiao, E., Lipps, C., Heffron, F., Salmonella typhimurium phoP virulence gene is a transcriptional regulator. Proc Natl Acad Sci USA 86 (1989) 7077-7081. 

Preiss, J. In press. Regulation of glycogen synthesis. In Escherichia coli and Salmonella typhimurium Cellular and Molecular Biology (F. C. Neidhardt, ed.), 2nd ed. Washington, DC, American Society of Microbiologist. 

A methylesterase which catalyzes the hydrolysis of y-glu-tamyl methyl esters of membrane bound proteins in Salmonella typhimurium and JJ. coli has recently been identified (25). Apparently, these membrane-bound proteins undergo methylation by a S-adenosylmethionine requiring methyltransferase (similar to transferase II). In this case the methylation and demethylation are directly associated with the chemotactic mobility of the microorganisms. When the cells are exposed to a chemotactic attractant, methylation of the membrane-bound proteins increases and straight-line movement up the gradient is induced. When the attractant is removed or a repellent substituted, the esterase decreases the methylation and random movement results. These control mechanisms are analogous in regulation to some of the reversible processes such as adenylation (26), uridylation (27) and phosphorylation (28). 

Several aaRS-like proteins are involved in metabobc pathways (1). For example, E. coli asparagine synthase, an aspartyl-tRNA synthetase (AspRS)-like enzyme, catalyzes the synthesis of asparagine from aspartate and ATP. A paralog of LysRS-II, called PoxA/GenX, is important for pyruvate oxidase activity in E. coli and Salmonella typhimurium and for virulence in S. typhimurium. The E. coli biotin synthetase/repressor protein (BirA), which has a domain that resembles structurally the seryl-tRNA synthetase (SerRS) catalytic domain, activates biotin to modify posttranslationaUy various metabolic proteins involved in carboxylation and decarboxylation. BirA can also bind DNA and regulate its own transcription using biotin as a corepressor. A histidyl-tRNA synthetase (HisRS)-hke protein from Lactococcus lactis, HisZ is involved in the allosteric activation of the phosphoribosyl-transferase reaction. 

AHLs are found only in Gram-negative bacteria, whereas AI-2 regulates phenotypes in genera as diverse as the firmicute B. subtilis and the y-proteobacterium V. harveyi. As a result, AI-2 has been proposed to be involved in interspecies communication (23). Homologues of LuxQ have only been found in Vibrio species. Therefore, it can be assumed that sensing of AI-2 occurs in a different way in other species. For example, in E. coli and Salmonella typhimurium, AI-2 is imported into... 

Trovafloxacin may down-regulate cytokine mRNA transcription in human peripheral blood mononuclear cells stimulated with lipopolysaccharide or lipoteichoic acid (2). Likewise, trovafloxacin inhibited Salmonella typhimurium-induced production of TNFa, HIV-1 replication, and reactivation of latent HIV-1 in promonocytic U1 cells at concentrations comparable to the plasma and tissue concentrations achieved by therapeutic dosages (3). 

Debnath, A.K., Compadre, R.L.L., Shusterman, A.J. and Hansch, C. (1992b). Quantitative Structure-Activity Relationship Investigation of the Role of Hydrophobicity in Regulating Mutagenicity in the Ames Test 2. Mutagenicity of Aromatic and Heteroaromatic Nitro Compounds in Salmonella typhimurium TAIOO. Environ.MoLMutagen., 19, 53-70. 

PEPCs from enterobacteria such as Salmonella typhimurium and Escherichia coli are activated by acetyl CoA and inhibited by aspartate. Some properties of the enzyme from Rhodopseudomonas sp. No.7 were similar to those of the enterobacteria. However, the strain No.7 enzyme was different from enzymes of the enterobacteria in important points of metabolic regulation. It have been reported that the enzyme activities of the enterobacteria were increased by FBP and GTP. In contrast with this, the activity of the No.7 enzyme was not affected by FBP and reversibly inhibited by GTP and ATP (ADP). This differences may signify roles of the enzyme of strain No.7 related to the ethanol-assimilation and the enzymes of the enterobacteria to the glucose-assimilation in their own way. 

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