Structure of the Escherichia coli signal transducing protein PII

Cheah, Eong; Carr, P.D.; Suffolk, P. M.; Vasudevan, Subhash G.; Dixon, Nicholas E.; Ollis, David L.

doi:10.1016/s0969-2126(94)00100-6

Cited by 82 publications

(105 citation statements)

References 45 publications

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“…The overall fold of GlnK is very similar to that of the uncomplexed protein (21). However, the T-loop exhibits a conformation that has not been seen previously in P II proteins (21,(31)(32)(33). It forms a short two-stranded antiparallel ␤-sheet (residues E44-Y46 and A49-Y51), the strands of which are separated by a ␤-turn.…”

Section: Resultsmentioning

confidence: 61%

“…In each of the four previous P II structures in which the T-loop was ordered, the ability to resolve the loop is a direct consequence of stabilization of the structure by crystal-packing contacts (21,(31)(32)(33). Although two of the previous structures exhibit an extended conformation, in each of those cases this is a consequence of extension of ␤-strands 2 and 3 (32,33).…”

Section: Discussionmentioning

confidence: 97%

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The crystal structure of the Escherichia coli AmtB–GlnK complex reveals how GlnK regulates the ammonia channel

Conroy

Durand

Lupo

et al. 2007

Proc. Natl. Acad. Sci. U.S.A.

167

257

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Amt proteins are ubiquitous channels for the conduction of ammonia in archaea, eubacteria, fungi, and plants. In Escherichia coli, previous studies have indicated that binding of the P II signal transduction protein GlnK to the ammonia channel AmtB regulates the channel thereby controlling ammonium influx in response to the intracellular nitrogen status. Here, we describe the crystal structure of the complex between AmtB and GlnK at a resolution of 2.5 Å. This structure of P II in a complex with one of its targets reveals physiologically relevant conformations of both AmtB and GlnK. GlnK interacts with AmtB almost exclusively via a long surface loop containing Y51 (T-loop), the tip of which inserts deeply into the cytoplasmic pore exit, blocking ammonia conduction. Y51 of GlnK is also buried in the pore exit, explaining why uridylylation of this residue prevents complex formation.regulation ͉ x-ray structure ͉ PII protein

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Section: Resultsmentioning

confidence: 61%

Section: Discussionmentioning

confidence: 97%

The crystal structure of the Escherichia coli AmtB–GlnK complex reveals how GlnK regulates the ammonia channel

Conroy

Durand

Lupo

et al. 2007

Proc. Natl. Acad. Sci. U.S.A.

167

257

View full text Add to dashboard Cite

show abstract

“…It has been found in archaea and bacteria, as well as in algae and plants. In Escherichia coli, the paradigm for P II structure and function in bacteria, P II is modified by uridylylation at a conserved Y51 residue, located at the tip of a solvent-exposed loop (Cheah et al, 1994 ;Jaggi et al, 1996). In contrast, the P II protein of the cyanobacterium Synechococcus sp.…”

Section: Introductionmentioning

confidence: 99%

The signal transducer PII and bicarbonate acquisition in Prochlorococcus marinus PCC 9511, a marine cyanobacterium naturally deficient in nitrate and nitrite assimilation a aThe GenBank accession number for the glnB gene sequence reported in this paper is AJ271089.

et al. 2002

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The amino acid sequence of the signal transducer P II (GlnB) of the oceanic photosynthetic prokaryote Prochlorococcus marinus strain PCC 9511 displays a typical cyanobacterial signature and is phylogenetically related to all known cyanobacterial glnB genes, but forms a distinct subclade with two other marine cyanobacteria. P II of P. marinus was not phosphorylated under the conditions tested, despite its highly conserved primary amino acid sequence, including the seryl residue at position 49, the site for the phosphorylation of the protein in the cyanobacterium Synechococcus PCC 7942. Moreover, P. marinus lacks nitrate and nitrite reductase activities and does not take up nitrate and nitrite. This strain, however, expresses a low-and a high-affinity transport system for inorganic carbon (C i ; K m,app 240 and 4 µM, respectively), a result consistent with the unphosphorylated form of P II acting as a sensor for the control of C i acquisition, as proposed for the cyanobacterium Synechocystis PCC 6803. The present data are discussed in relation to the genetic information provided by the P. marinus MED4 genome sequence.

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“…In K. pneumoniae, GlnK, but not GlnB, regulates the interaction of NifL and NifA to control the expression of the nif operons (8,9). The x-ray crystal structures of GlnB and GlnK from E. coli have been solved (10,11). The monomer structures of GlnB and GlnK are very similar and contain two ␣-helices and six ␤-strands, connected by three loops.…”

mentioning

confidence: 99%

“…2). These three clefts were believed to be important for P II to interact with different targets (11,12).…”

mentioning

confidence: 99%

Identification of critical residues in GlnB for its activation of NifA activity in the photosynthetic bacterium Rhodospirillum rubrum

Zhang

Pohlmann

Roberts

2004

Proc. Natl. Acad. Sci. U.S.A.

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The PII regulatory protein family is unusually widely distributed, being found in all three domains of life. Three P II homologs called GlnB, GlnK, and GlnJ have been identified in the photosynthetic bacterium Rhodospirillum rubrum. These have roles in at least four distinct functions, one of which is activation of the nitrogen fixation-specific regulatory protein NifA. The activation of NifA requires only the covalently modified (uridylylated) form of GlnB. GlnK and GlnJ are not involved. However, the basis of specificity for different P II homologs in different processes is poorly understood. We examined this specificity by altering GlnJ to support NifA activation. A small number of amino acid substitutions in GlnJ were important for this ability. Two (affecting residues 45 and 54) are in a loop called the T-loop, which contains the site of uridylylation and is believed to be very important for contacts with other proteins, but other critical residues lie in the C terminus (residues 95-97 and 109 -112) and near the N terminus (residues 3-5 and 17). Because many of the residues important for P II-NifA interaction lie far from the T-loop in the known x-ray crystal structures of P II proteins, our results lead to the hypothesis that the T-loop of GlnB is flexible enough to come into proximity with both the C-and N-terminal regions of the protein to bind NifA. Finally, the results show that the level of P II accumulation is also an important factor for NifA activation.

show abstract

Structure of the Escherichia coli signal transducing protein PII

Abstract: The structure of PII suggests potential regions of interaction with other proteins and serves as an initial step in understanding its signal transducing role in nitrogen regulation.

Cited by 82 publications

References 45 publications

The crystal structure of the Escherichia coli AmtB–GlnK complex reveals how GlnK regulates the ammonia channel

The crystal structure of the Escherichia coli AmtB–GlnK complex reveals how GlnK regulates the ammonia channel

The signal transducer PII and bicarbonate acquisition in Prochlorococcus marinus PCC 9511, a marine cyanobacterium naturally deficient in nitrate and nitrite assimilation a aThe GenBank accession number for the glnB gene sequence reported in this paper is AJ271089.

Identification of critical residues in GlnB for its activation of NifA activity in the photosynthetic bacterium Rhodospirillum rubrum

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