1ka5
From Proteopedia
Refined Solution Structure of Histidine Containing Phosphocarrier Protein from Staphyloccocus aureus
Structural highlights
FunctionPTHP_STAAU General (non sugar-specific) component of the phosphoenolpyruvate-dependent sugar phosphotransferase system (sugar PTS). This major carbohydrate active-transport system catalyzes the phosphorylation of incoming sugar substrates concomitantly with their translocation across the cell membrane. The phosphoryl group from phosphoenolpyruvate (PEP) is transferred to the phosphoryl carrier protein HPr by enzyme I. Phospho-HPr then transfers it to the permease (enzymes II/III). P-Ser-HPr interacts with the catabolite control protein A (CcpA), forming a complex that binds to DNA at the catabolite response elements cre, operator sites preceding a large number of catabolite-regulated genes. Thus, P-Ser-HPr is a corepressor in carbon catabolite repression (CCR), a mechanism that allows bacteria to coordinate and optimize the utilization of available carbon sources. P-Ser-HPr also plays a role in inducer exclusion, in which it probably interacts with several non-PTS permeases and inhibits their transport activity (By similarity). Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedA high-resolution structure of the histidine-containing phosphocarrier protein (HPr) from Staphylococcus aureus was obtained by heteronuclear multidimensional nuclear magnetic resonance (NMR) spectroscopy on the basis of 1,766 structural restraints. Twenty-three hydrogen bonds in HPr could be directly detected by polarization transfer from the amide nitrogen to the carbonyl carbon involved in the hydrogen bond. Differential line broadening was used to characterize the interaction of HPr with the HPr kinase/phosphorylase (HPrK/P) of Staphylococcus xylosus, which is responsible for phosphorylation-dephosphorylation of the hydroxyl group of the regulatory serine residue at position 46. The dissociation constant Kd was determined to be 0.10 +/- 0.02 mM at 303 K from the NMR data, assuming independent binding. The data are consistent with a stoichiometry of 1 HPr molecule per HPrK/P monomer in solution. Using transversal relaxation optimized spectroscopy-heteronuclear single quantum correlation, we mapped the interaction site of the two proteins in the 330-kDa complex. As expected, it covers the region around Ser46 and the small helix b following this residue. In addition, HPrK/P also binds to the second phosphorylation site of HPr at position 15. This interaction may be essential for the recognition of the phosphorylation state of His15 and the phosphorylation-dependent regulation of the kinase/phosphorylase activity. In accordance with this observation, the recently published X-ray structure of the HPr/HPrK core protein complex from Lactobacillus casei shows interactions with the two phosphorylation sites. However, the NMR data also suggest differences for the full-length protein from S. xylosus: there are no indications for an interaction with the residues preceding the regulatory Ser46 residue (Thr41 to Lys45) in the protein of S. xylosus. In contrast, it seems to interact with the C-terminal helix of HPr in solution, an interaction which is not observed for the complex of HPr with the core of HPrK/P of L. casei in crystals. High-resolution structure of the histidine-containing phosphocarrier protein (HPr) from Staphylococcus aureus and characterization of its interaction with the bifunctional HPr kinase/phosphorylase.,Maurer T, Meier S, Kachel N, Munte CE, Hasenbein S, Koch B, Hengstenberg W, Kalbitzer HR J Bacteriol. 2004 Sep;186(17):5906-18. PMID:15317796[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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