ptsI

..Furthermore, phosphotransfer between acyl residues: P-aspartyl to glutamyl and P-glutamyl to aspartyl was demonstrated with these mutant proteins and enzymes...

..coli K-12. These retain the DeltaagaW' EF 'A deletion and carry suppressor mutations in the gat and nag genes for galactitol and N-acetyl-glucosamine metabolism, respectively, that allow growth on Aga but not on GalN...

..Promoter-reporter gene fusion studies identified two CRP.cAMP-dependent promoters (the previously identified P1 and another promoter, P0) upstream of ptsH. The crr promoters (P2) within ptsI may be negatively regulated by CRP.cAMP.

The ptsH, ptsI, and crr genes, coding for three of the proteins of the phosphoenolpyruvate-dependent phosphotransferase system (PTS) (HPr, enzyme I, and enzyme IIIGlc, respectively) have been studied by determination of their nucleotide ..

..C., Kapadia, G., McGuire, M., Carroll, L. J., Noh, S. J., and Dunaway-Mariano, D. (1996) Proc. Natl. Acad. Sci. U. S. A. 93, 2652-2657)), which brings the C-terminal domain with the two bound ligands close to the active site His(189)...

..The manXYZ-encoded PTS transporter makes a minor contribution to the formation of cytoplasmic GlcNAc6P but appears to have a more important role in secretion of GlcNAc and/or GlcNAc6P from the cytoplasm...

..We also examined whether the H-NS homolog StpA has such an adapter function, as was previously proposed. Our results did not support the idea that StpA has an adapter function in the genetic background used...

..e. glucose and GlcNAc. Presumably the PTS sugars inhibit by competing for PTS components. Kinetic properties of the transport system are described...

..This is apparently the first report of the isolation of a transition state analogue in a protein-protein phosphotransfer reaction...

..Similarly, a common surface on IIA(Glc) interacts with HPr, IIB(Glc) and glycerol kinase. Thus, there is a common motif for the protein-protein interactions characteristic of the PTS...

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..The mlc gene is shown to be allelic with the previously characterized dgsA mutation affecting the mannose phosphoenolpyruvate-dependent phosphotransferase system (PTS)...

..The DNA-binding function of the H-NS-like protein StpA was found to be necessary for repression, which is consistent with a role for StpA as a DNA-binding adapter for mutant derivatives of H-NS...

..A leuO deletion mutant was also characterized in terms of expression of bgl. From these results, the possible function of LeuO in bgl expression will be discussed from an evolutionary and/or ecological point of view...

..Furthermore, sequencing evidence indicates that the operon contains an additional gene of unknown function to be designated as chbG. Thus, the overall gene sequence is to be named chbBCARFG...

..Thus, the mapping reported here is an important step toward the definition of the functional domains involved in the transduction of a signal by the components that constitute systems of this novel family...

..Implications for bgl operon regulation by global regulators H-NS, RpoS and others are discussed...

..The physiological significance of these differences is discussed in the context of survival of natural populations of E. coli...

..A working model that accounts for the kinetic data is presented...

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..Such design and analysis predicted that the mlc knockout mutant with ptsI gene overexpression would greatly increase the specific glucose uptake rate...

..Therefore, they may constitute a signature motif that determines the specificity of HPr for either gram-negative or -positive EIIs...

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..This condition is responsible of the utilization of secondary carbon sources in the presence of glucose...

..Finally, a lactoperoxidase tolerant knock-out strain of ulaA, involved in ascorbic acid uptake, did not show resistance to any of the other oxidants. The possible modes of action of these different oxidants are discussed...

..In PB12, glk, pgi, the TCA cycle and certain respiratory genes are also upregulated. A mutation in arcB in PB12 is apparently responsible for the upregulation of the TCA cycle and certain respiratory genes...

..These results suggest that the Sga and Gat families of PTS permeases comprise a small superfamily in which the transmembrane IIC domains evolved independently of all other known PTS permeases...

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..Close homologs of MurP were identified in the genome of several bacteria, and we believe that these organisms might also be able to utilize MurNAc...

..Glucose effects mediated by other global regulators cannot be ruled out with the present information. Changes in cAMP-CRP levels affected only the expression of the ulaABCDEF operon...

..Thus, MngR is the regulator (repressor) of the MG transport/metabolism system. Thus, the mngR mngA mngB gene cluster encodes an MG utilizing system...

..Our results imply that the monomer-dimer transition involves a conformational change. The possible role of the compact form in preventing untimely induction of the bgl operon is discussed...

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..The protein fold of IIBLev has no similarity to any of the known structures of other phosphoenolpyruvate-dependent-carbohydrate-phosphotransferase-system proteins...

..An additional cistron of the gut operon, of unknown function, may follow the gutR gene...

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..subtilis, for which data pertaining to regulation are not yet available, suggest a close evolutionary relationship among the regulatory components of all three systems...

..The role of the insertion sequences in activation of the bgl operon is discussed...

..Addition of inducer stimulates BglF to dephosphorylate BglG, allowing BglG to function as a positive regulator of operon expression. Beta-Glucosides are then phosphorylated and transported into the cell by BglF...

..sequence of an Escherichia coli DNA segment containing the ptsH gene and the first 162 nucleotides of the ptsI gene encoding, respectively, Hpr and enzyme I of the phosphoenolpyruvate-dependent glycose phosphotransferase ..

..The bgl operon is thus regulated by a sensory system that modulates gene expression by protein phosphorylation and dephosphorylation in response to the external levels of inducer...

..The nagD gene is followed by repetitive extragenic palindromic sequences. The nag genes appear to be organized in an operon: nagD nagC nagA nagB nagE...

..We conclude that the genes for these two enzyme IIIs diverged much more recently than did their hosts, indicating that E. coli and S. aureus have undergone relatively recent exchange of chromosomal genes...

..The phenotype of this mutant indicated that trehalose-6-phosphate is the effective in vivo inducer of the system...

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..This may be important for the interaction with the IIB domain of the permease and/or play a catalytic role in the phosphoryl transfer from IIA to IIB...

..This is not the case in a malT(Con) strain that expresses the mal genes constitutively. We conclude that malY encodes an enzyme that degrades the inducer of the maltose system or prevents its synthesis...

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..We propose that the bglC gene product mediates positive regulation of the bgl operon by functioning as an antiterminator at the rho-independent terminator located within the leader...

..It is concluded that streptozotocin is taken up by E. coli via the phosphoenolpyruvate:sugar phosphotransferase system and consequently accumulates in the cell at first as streptozotocin-phosphate...

..The phosphorylation site (Cys421) is at the end of beta 1 on the solvent-exposed face of the sheet surrounded by Asp419, Thr423 Arg424, Arg426, and Gln456 which are invariant in 15 homologous IIB domains from other PTS transporters...

..Modeling suggests that the covalently bound phosphoryl group would be stabilized by the macrodipole of helix C. Putative interactions between IIA(Man) and the histidine-containing phosphocarrier protein are discussed...

..It is suggested that both the frv and glv operons are cryptic in E. coli and that additional genes encoding novel PTS-related proteins will be revealed by bacterial genome sequence analyses...

..6 A, b = 31.7 A, c = 60.0 A and beta = 101.7 degrees. From a self-rotation function it seems likely that there are two molecules in the asymmetric unit related by a non-crystallographic 2-fold axis...

..Instead, enzyme IITre-mediated phosphorylation of trehalose requires the activity of enzyme IIAGlc, a component of the major glucose transport system...

..coli populations, and that all of these are normally cryptic. It is estimated that in any random isolate the probability of any particular cluster having been irreversibly inactivated by the accumulation of random mutations is about 0.5...

..Activation of gene expression by means of interaction of a defective mobile element in cis with functions encoded by a nondefective element in trans has so far been described only for a maize controlling element...

..A pathway for the metabolism of N-acetylgalactosamine biochemically similar to that for the metabolism of N-acetylglucosamine is proposed...

..coli can express two H-NS-like proteins with coordinated yet differential regulation. Evidently, these proteins have both overlapping and distinct functions in the cell, and they are both important for normal cell growth and gene control...

..This result supports the notion that the bgl system is a member of a new family of bacterial sensory systems...

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..The transition state can be formed with minimal changes in overall conformation, and is stabilized in favor of phosphorylated HPr, thereby accounting for the directionality of phosphoryl transfer...

..In gram-positive bacteria, it has been demonstrated that HPr can be phosphorylated by ATP on a serine residue and this modification may perform a regulatory function...

..Computer searches revealed the presence of this sequence in numerous functionally diverse operons, implying that FruR is a global transcriptional regulatory protein in enteric bacteria...

..Genetic studies indicate that the increased resistance toward phosphonomycin and temperature sensitivity in growth of this mutant are probably the consequences of a single mutation...

..The active His-208-phosphorylated BglG dimer can subsequently be inhibited in its activity by EIIBgl-catalyzed phosphorylation at His-101...

The expression of genes adjacent to ptsI was investigated using a series of specialised transducing phages carrying different, overlapping, segments of the cysA-gsr-ptsI-ptsH- iex - cysZ -lig region of the genome of Escherichia coli...

..The fru operon is regulated by a repressor, FruR. We have constructed an operon fusion between fru and the galK gene and shown that regulation of the fru operon by FruR takes place at the level of transcription...

..The resulting mutants will then be characterized to determine which kind of data most accurately predicted the eventual evolutionary outcome. ..

..abstract_text> ..

..6) Develop approaches that will allow integration of the different lines of functional information revealed in specific aims #4 and 5. ..

..The knowledge gained should be applicable to the control of pathogenic bacteria. The protein kinase-mediated regulatory processes under study are expected to be relevant to analogous processes in eukaryotic organisms. ..

..6) Develop approaches that will allow integration of the different lines of functional information revealed in specific aims #4 and 5. ..