5t12
N-terminal domain of Enzyme 1 - NitrogenN-terminal domain of Enzyme 1 - Nitrogen
Structural highlights
FunctionPT1P_ECOLI Component of the phosphoenolpyruvate-dependent nitrogen-metabolic phosphotransferase system (nitrogen-metabolic PTS), that seems to be involved in regulating nitrogen metabolism. Enzyme I-Ntr transfers the phosphoryl group from phosphoenolpyruvate (PEP) to the phosphoryl carrier protein (NPr) (PubMed:10473571). Could function in the transcriptional regulation of sigma-54 dependent operons in conjunction with the NPr (PtsO) and EIIA-Ntr (PtsN) proteins (PubMed:8973315). Enzyme I-Ntr is specific for NPr (PubMed:10473571).[1] [2] Publication Abstract from PubMedParalogous enzymes arise from gene duplication events that confer a novel function, although it is unclear how cross-reaction between the original and duplicate protein interaction network is minimized. We investigated HPr:EIsugar and NPr:EINtr, the initial complexes of paralogous phosphorylation cascades involved in sugar import and nitrogen regulation in bacteria, respectively. Although the HPr:EIsugar interaction has been well characterized, involving multiple complexes and transient interactions, the exact nature of the NPr:EINtr complex was unknown. We set out to identify the key features of the interaction by performing binding assays and elucidating the structure of NPr in complex with the phosphorylation domain of EINtr (EINNtr), using a hybrid approach involving X-ray, homology, and sparse nuclear magnetic resonance. We found that the overall fold and active-site structure of the two complexes are conserved in order to maintain productive phosphorylation, however, the interface surface potential differs between the two complexes, which prevents cross-reaction. Structure of the NPr:EINNtr Complex: Mechanism for Specificity in Paralogous Phosphotransferase Systems.,Strickland M, Stanley AM, Wang G, Botos I, Schwieters CD, Buchanan SK, Peterkofsky A, Tjandra N Structure. 2016 Dec 6;24(12):2127-2137. doi: 10.1016/j.str.2016.10.007. Epub 2016, Nov 10. PMID:27839951[3] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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