A. J. Ninfa

The Caulobacter crescentus FlbD protein acts at ftr sequence elements both to activate and to repress transcription of cell cycle-regulated flagellar genes.

Benson, A K, Ramakrishnan, G, Ohta, N, Feng, J, Ninfa, A J, Newton, A

The flagellar genes (fla genes) in Caulobacter crescentus are organized into a regulatory hierarchy of four levels, I-IV, in which transcription of the class III and class IV genes late in the cell...

Inhibitors of two-component signal transduction systems: inhibition of alginate gene activation in Pseudomonas aeruginosa.

Roychoudhury, S, Zielinski, N A, Ninfa, A J, Allen, N E, Jungheim, L N, Nicas, T I, ...

Pseudomonas aeruginosa strains infecting cystic fibrosis patients often produce copious amounts of the exopolysaccharide alginate. Expression of alginate genes in P. aeruginosa is regulated by...

Activation of transcription initiation from the nac promoter of Klebsiella aerogenes.

Feng, J, Goss, T J, Bender, R A, Ninfa, A J

The nac gene of Klebsiella aerogenes encodes a bifunctional transcription factor that activates or represses the expression of several operons under conditions of nitrogen limitation. In experiments...

Repression of the Klebsiella aerogenes nac promoter.

Feng, J, Goss, T J, Bender, R A, Ninfa, A J

Transcription of the nitrogen-regulated nac promoter of Klebsiella aerogenes requires sigma54 RNA polymerase, is activated by the phosphorylated form of the transcription factor nitrogen regulator I...

Identification, characterization, and chromosomal organization of cell division cycle genes in Caulobacter crescentus.

Ohta, N, Ninfa, A J, Allaire, A, Kulick, L, Newton, A

We report a detailed characterization of cell division cycle (cdc) genes in the differentiating gram-negative bacterium Caulobacter crescentus. A large set of temperature-sensitive cdc mutations was...

Structure/function analysis of the PII signal transduction protein of Escherichia coli: genetic separation of interactions with protein receptors.

Jiang, P, Zucker, P, Atkinson, M R, Kamberov, E S, Tirasophon, W, Chandran, P, ...

The PII protein, encoded by glnB, is known to interact with three bifunctional signal transducing enzymes (uridylyltransferase/uridylyl-removing enzyme, adenylyltransferase, and the...

Probing interactions of the homotrimeric PII signal transduction protein with its receptors by use of PII heterotrimers formed in vitro from wild-type and mutant subunits.

Jiang, P, Zucker, P, Ninfa, A J

The homotrimeric PII signal transduction protein of Escherichia coli interacts with two small-molecule effectors, 2-ketoglutarate and ATP, regulates two protein receptors, the kinase/phosphatase...

Characterization of Escherichia coli glnL mutations affecting nitrogen regulation.

Atkinson, M R, Ninfa, A J

Nitrogen regulator II (NRII), the product of the Escherichia coli glnL (ntrB) gene, regulates the activation of transcription of glnA and the Ntr regulon by catalyzing the phosphorylation and...

Characterization of the regulon controlled by the leucine-responsive regulatory protein in Escherichia coli.

Ernsting, B R, Atkinson, M R, Ninfa, A J, Matthews, R G

The leucine-responsive regulatory protein (Lrp) has been shown to regulate, either positively or negatively, the transcription of several Escherichia coli genes in response to leucine. We have used...

Mutational analysis of the bacterial signal-transducing protein kinase/phosphatase nitrogen regulator II (NRII or NtrB).

Atkinson, M R, Ninfa, A J

The signal-transducing kinase/phosphatase nitrogen regulator II (NRII or NtrB) is required for the efficient positive and negative regulation of glnA, encoding glutamine synthetase, and the Ntr...

Mechanism of autophosphorylation of Escherichia coli nitrogen regulator II (NRII or NtrB): trans-phosphorylation between subunits.

Ninfa, E G, Atkinson, M R, Kamberov, E S, Ninfa, A J

Nitrogen regulator II (NRII or NtrB) is a homodimeric signal-transducing protein kinase/phosphatase responsible for the transcriptional regulation of the Ntr regulon in Escherichia coli. NRII is a...

Role of phosphorylated metabolic intermediates in the regulation of glutamine synthetase synthesis in Escherichia coli.

Feng, J, Atkinson, M R, McCleary, W, Stock, J B, Wanner, B L, Ninfa, A J

Transcription of the Ntr regulon is controlled by the two-component system consisting of the response regulator NRI (NtrC) and the kinase/phosphatase NRII (NtrB), which both phosphorylates and...

Escherichia coli sigma 54 RNA polymerase recognizes Caulobacter crescentus flbG and flaN flagellar gene promoters in vitro.

Ninfa, A J, Mullin, D A, Ramakrishnan, G, Newton, A

A set of the periodically regulated flagellar (fla) genes of Caulobacter crescentus contain conserved promoter sequence elements at -24 and -12 that are very similar to the sequence of the nitrogen...

Mutations in the glnG gene of Escherichia coli that result in increased activity of nitrogen regulator I.

Weglenski, P, Ninfa, A J, Ueno-Nishio, S, Magasanik, B

Mutations in the glnG gene of Escherichia coli that result in increased activity of nitrogen regulator I (NRI), the product of glnG, were obtained by two different selection procedures. The mutant...

Purification of nitrogen regulator II, the product of the glnL (ntrB) gene of Escherichia coli.

Ninfa, A J, Ueno-Nishio, S, Hunt, T P, Robustell, B, Magasanik, B

We purified the product of glnL (ntrB), NRII, and the product of a mutant glnL allele, NRII2302. In vitro transcription of the nitrogen-regulated promoter glnAp2 by purified components of Escherichia...

Crosstalk between bacterial chemotaxis signal transduction proteins and regulators of transcription of the Ntr regulon: evidence that nitrogen assimilation and chemotaxis are controlled by a common phosphotransfer mechanism.

Ninfa, A J, Ninfa, E G, Lupas, A N, Stock, A, Magasanik, B, Stock, J

We demonstrate by using purified bacterial components that the protein kinases that regulate chemotaxis and transcription of nitrogen-regulated genes, CheA and NRII, respectively, have...

Protein phosphorylation and regulation of adaptive responses in bacteria.

Stock, J B, Ninfa, A J, Stock, A M

Bacteria continuously adapt to changes in their environment. Responses are largely controlled by signal transduction systems that contain two central enzymatic components, a protein kinase that uses...

Covalent modification of the glnG product, NRI, by the glnL product, NRII, regulates the transcription of the glnALG operon in Escherichia coli.

Ninfa, A J, Magasanik, B

Transcription from nitrogen-regulated promoters, such as glnAp2, requires the glnG gene product, NRI, as well as the rpoN(glnF) gene product, sigma60, and is regulated by the glnL gene product, NRII....

The Caulobacter crescentus FlbD protein acts at ftr sequence elements both to activate and to repress transcription of cell cycle-regulated flagellar genes.

Benson, A K, Ramakrishnan, G, Ohta, N, Feng, J, Ninfa, A J, Newton, A

The flagellar genes (fla genes) in Caulobacter crescentus are organized into a regulatory hierarchy of four levels, I-IV, in which transcription of the class III and class IV genes late in the cell...

Inhibitors of two-component signal transduction systems: inhibition of alginate gene activation in Pseudomonas aeruginosa.

Roychoudhury, S, Zielinski, N A, Ninfa, A J, Allen, N E, Jungheim, L N, Nicas, T I, ...

Pseudomonas aeruginosa strains infecting cystic fibrosis patients often produce copious amounts of the exopolysaccharide alginate. Expression of alginate genes in P. aeruginosa is regulated by...

Activation of transcription initiation from the nac promoter of Klebsiella aerogenes.

Feng, J, Goss, T J, Bender, R A, Ninfa, A J

The nac gene of Klebsiella aerogenes encodes a bifunctional transcription factor that activates or represses the expression of several operons under conditions of nitrogen limitation. In experiments...

Repression of the Klebsiella aerogenes nac promoter.

Feng, J, Goss, T J, Bender, R A, Ninfa, A J

Transcription of the nitrogen-regulated nac promoter of Klebsiella aerogenes requires sigma54 RNA polymerase, is activated by the phosphorylated form of the transcription factor nitrogen regulator I...

Identification, characterization, and chromosomal organization of cell division cycle genes in Caulobacter crescentus.

Ohta, N, Ninfa, A J, Allaire, A, Kulick, L, Newton, A

We report a detailed characterization of cell division cycle (cdc) genes in the differentiating gram-negative bacterium Caulobacter crescentus. A large set of temperature-sensitive cdc mutations was...

Structure/function analysis of the PII signal transduction protein of Escherichia coli: genetic separation of interactions with protein receptors.

Jiang, P, Zucker, P, Atkinson, M R, Kamberov, E S, Tirasophon, W, Chandran, P, ...

The PII protein, encoded by glnB, is known to interact with three bifunctional signal transducing enzymes (uridylyltransferase/uridylyl-removing enzyme, adenylyltransferase, and the...

Probing interactions of the homotrimeric PII signal transduction protein with its receptors by use of PII heterotrimers formed in vitro from wild-type and mutant subunits.

Jiang, P, Zucker, P, Ninfa, A J

The homotrimeric PII signal transduction protein of Escherichia coli interacts with two small-molecule effectors, 2-ketoglutarate and ATP, regulates two protein receptors, the kinase/phosphatase...

Characterization of Escherichia coli glnL mutations affecting nitrogen regulation.

Atkinson, M R, Ninfa, A J

Nitrogen regulator II (NRII), the product of the Escherichia coli glnL (ntrB) gene, regulates the activation of transcription of glnA and the Ntr regulon by catalyzing the phosphorylation and...

Characterization of the regulon controlled by the leucine-responsive regulatory protein in Escherichia coli.

Ernsting, B R, Atkinson, M R, Ninfa, A J, Matthews, R G

The leucine-responsive regulatory protein (Lrp) has been shown to regulate, either positively or negatively, the transcription of several Escherichia coli genes in response to leucine. We have used...

Mutational analysis of the bacterial signal-transducing protein kinase/phosphatase nitrogen regulator II (NRII or NtrB).

Atkinson, M R, Ninfa, A J

The signal-transducing kinase/phosphatase nitrogen regulator II (NRII or NtrB) is required for the efficient positive and negative regulation of glnA, encoding glutamine synthetase, and the Ntr...

Mechanism of autophosphorylation of Escherichia coli nitrogen regulator II (NRII or NtrB): trans-phosphorylation between subunits.

Ninfa, E G, Atkinson, M R, Kamberov, E S, Ninfa, A J

Nitrogen regulator II (NRII or NtrB) is a homodimeric signal-transducing protein kinase/phosphatase responsible for the transcriptional regulation of the Ntr regulon in Escherichia coli. NRII is a...

Role of phosphorylated metabolic intermediates in the regulation of glutamine synthetase synthesis in Escherichia coli.

Feng, J, Atkinson, M R, McCleary, W, Stock, J B, Wanner, B L, Ninfa, A J

Transcription of the Ntr regulon is controlled by the two-component system consisting of the response regulator NRI (NtrC) and the kinase/phosphatase NRII (NtrB), which both phosphorylates and...

Escherichia coli sigma 54 RNA polymerase recognizes Caulobacter crescentus flbG and flaN flagellar gene promoters in vitro.

Ninfa, A J, Mullin, D A, Ramakrishnan, G, Newton, A

A set of the periodically regulated flagellar (fla) genes of Caulobacter crescentus contain conserved promoter sequence elements at -24 and -12 that are very similar to the sequence of the nitrogen...

Mutations in the glnG gene of Escherichia coli that result in increased activity of nitrogen regulator I.

Weglenski, P, Ninfa, A J, Ueno-Nishio, S, Magasanik, B

Mutations in the glnG gene of Escherichia coli that result in increased activity of nitrogen regulator I (NRI), the product of glnG, were obtained by two different selection procedures. The mutant...

Purification of nitrogen regulator II, the product of the glnL (ntrB) gene of Escherichia coli.

Ninfa, A J, Ueno-Nishio, S, Hunt, T P, Robustell, B, Magasanik, B

We purified the product of glnL (ntrB), NRII, and the product of a mutant glnL allele, NRII2302. In vitro transcription of the nitrogen-regulated promoter glnAp2 by purified components of Escherichia...

Crosstalk between bacterial chemotaxis signal transduction proteins and regulators of transcription of the Ntr regulon: evidence that nitrogen assimilation and chemotaxis are controlled by a common phosphotransfer mechanism.

Ninfa, A J, Ninfa, E G, Lupas, A N, Stock, A, Magasanik, B, Stock, J

We demonstrate by using purified bacterial components that the protein kinases that regulate chemotaxis and transcription of nitrogen-regulated genes, CheA and NRII, respectively, have...

Protein phosphorylation and regulation of adaptive responses in bacteria.

Stock, J B, Ninfa, A J, Stock, A M

Bacteria continuously adapt to changes in their environment. Responses are largely controlled by signal transduction systems that contain two central enzymatic components, a protein kinase that uses...

Covalent modification of the glnG product, NRI, by the glnL product, NRII, regulates the transcription of the glnALG operon in Escherichia coli.

Ninfa, A J, Magasanik, B

Transcription from nitrogen-regulated promoters, such as glnAp2, requires the glnG gene product, NRI, as well as the rpoN(glnF) gene product, sigma60, and is regulated by the glnL gene product, NRII....