2a0j
From Proteopedia
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Crystal Structure of Nitrogen Regulatory Protein IIA-Ntr from Neisseria meningitidis
Overview
BACKGROUND: The NMB0736 gene of Neisseria meningitidis serogroup B strain MC58 encodes the putative nitrogen regulatory protein, IIANtr (abbreviated to NM-IIANtr). The homologous protein present in Escherichia coli is implicated in the control of nitrogen assimilation. As part of a structural proteomics approach to the study of pathogenic Neisseria spp., we have selected this protein for structure determination by X-ray crystallography. RESULTS: The NM-IIANtr was over-expressed in E. coli and was shown to be partially mono-phosphorylated, as assessed by mass spectrometry of the purified protein. Crystals of un-phosphorylated protein were obtained and diffraction data collected to 2.5 A resolution. The structure of NM-IIANtr was solved by molecular replacement using the coordinates of the E. coli nitrogen regulatory protein IIAntr [PDB: 1A6J] as the starting model. The overall fold of the Neisseria enzyme shows a high degree of similarity to the IIANtr from E. coli, and the position of the phosphoryl acceptor histidine residue (H67) is conserved. The orientation of an adjacent arginine residue (R69) suggests that it may also be involved in coordinating the phosphate group. Comparison of the structure with that of E. coli IIAmtl complexed with HPr [PDB: 1J6T] indicates that NM-IIANtr binds in a similar way to the HPr-like enzyme in Neisseria. CONCLUSION: The structure of NM-IIANtr confirms its assignment as a homologue of the IIANtr proteins found in a range of other Gram-negative bacteria. We conclude that the NM- IIANtr protein functions as part of a phosphorylation cascade which, in contrast to E. coli, shares the upstream phosphotransfer protein with the sugar uptake phosphoenolpyruvate:sugar phosphotransferase system (PTS), but in common with E. coli has a distinct downstream effector mechanism.
About this Structure
2A0J is a Single protein structure of sequence from Neisseria meningitidis. Active as Protein-N(pi)-phosphohistidine--sugar phosphotransferase, with EC number 2.7.1.69 Full crystallographic information is available from OCA.
Reference
Crystal structure of nitrogen regulatory protein IIANtr from Neisseria meningitidis., Ren J, Sainsbury S, Berrow NS, Alderton D, Nettleship JE, Stammers DK, Saunders NJ, Owens RJ, BMC Struct Biol. 2005 Aug 10;5:13. PMID:16092953
Page seeded by OCA on Thu Feb 21 16:22:25 2008
Categories: Neisseria meningitidis | Protein-N(pi)-phosphohistidine--sugar phosphotransferase | Single protein | Alderton, D. | Berrow, N S. | Nettleship, J E. | OPPF, Oxford Protein Production Facility. | Owens, R J. | Ren, J. | Sainsbury, S. | Saunders, N J. | Stammers, D K. | Nitrogen regulation | Oppf | Oxford protein production facility | Structural genomics
