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IPR015867

Nitrogen regulatory protein PII/ATP phosphoribosyltransferase, C-terminal

InterPro entry
Short nameN-reg_PII/ATP_PRibTrfase_C
Overlapping entries
 
UPF0166 (IPR003793)

Description

This entry represents a structural domain found in the nitrogen regulatory protein PII, in ATP phosphribosyltransferases (C-terminal domain), and in some bacterial hypothetical proteins. This domain consists of a ferredoxin-like α/β sandwich, which forms trimeric structures with orthogonally packed β-sheets around a three-fold axis.

PII is a tetrameric protein encoded by glnB that functions as a component of the adenylation cascade involved in the regulation of glutamine synthetase activity
[1]
. PII helps regulate the level of glutamine synthetase in response to nitrogen source availability. In nitrogen-limiting conditions, PII is uridylylated to form PII-UMP, which allows the deadenylation of glutamine synthetase, thus activating the enzyme. Conversely, in nitrogen excess, PI-UMP is deuridylated to PII, promoting the adenylation and deactivation of glutamine synthetase
[2]
.

ATP phosphoribosyltransferase is the first enzyme of the histidine pathway. It is allosterically regulated, controlling the flow of intermediates through the pathway. The C-terminal domain is the regulatory region of the protein, which binds the allosteric inhibitor histidine
[3]
.

References

1.Characterization of three different nitrogen-regulated promoter regions for the expression of glnB and glnA in Azospirillum brasilense. de Zamaroczy M, Delorme F, Elmerich C. Mol. Gen. Genet. 224, 421-30, (1990). View articlePMID: 1702507

2.Characterization of pII family (GlnK1, GlnK2, and GlnB) protein uridylylation in response to nitrogen availability for Rhodopseudomonas palustris. Connelly HM, Pelletier DA, Lu TY, Lankford PK, Hettich RL. Anal. Biochem. 357, 93-104, (2006). View articlePMID: 16860774

3.The structure of Escherichia coli ATP-phosphoribosyltransferase: identification of substrate binding sites and mode of AMP inhibition. Lohkamp B, McDermott G, Campbell SA, Coggins JR, Lapthorn AJ. J. Mol. Biol. 336, 131-44, (2004). View articlePMID: 14741209

Cross References

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