6EMN
HtxB from Pseudomonas stutzeri in complex with phosphite to 1.25 A resolution
Summary for 6EMN
| Entry DOI | 10.2210/pdb6emn/pdb |
| Related | 5ME4 |
| Descriptor | Probable phosphite transport system-binding protein HtxB, oxidanylphosphinate, MAGNESIUM ION, ... (5 entities in total) |
| Functional Keywords | periplasmic binding protein, phosphite, hypophosphite, abc-transporter, transport protein |
| Biological source | Pseudomonas stutzeri (Pseudomonas perfectomarina) |
| Total number of polymer chains | 1 |
| Total formula weight | 30563.96 |
| Authors | Bisson, C.,Robertson, A.J.,Hitchcock, A.,Adams, N.B. (deposition date: 2017-10-03, release date: 2019-04-17, Last modification date: 2024-01-17) |
| Primary citation | Adams, N.B.P.,Robertson, A.J.,Hunter, C.N.,Hitchcock, A.,Bisson, C. Phosphite binding by the HtxB periplasmic binding protein depends on the protonation state of the ligand. Sci Rep, 9:10231-10231, 2019 Cited by PubMed Abstract: Phosphorus acquisition is critical for life. In low phosphate conditions, some species of bacteria have evolved mechanisms to import reduced phosphorus compounds, such as phosphite and hypophosphite, as alternative phosphorus sources. Uptake is facilitated by high-affinity periplasmic binding proteins (PBPs) that bind cargo in the periplasm and shuttle it to an ATP-binding cassette (ABC)-transporter in the bacterial inner membrane. PtxB and HtxB are the PBPs responsible for binding phosphite and hypophosphite, respectively. They recognize the P-H bond of phosphite/hypophosphite via a conserved P-H...π interaction, which confers nanomolar dissociation constants for their respective ligands. PtxB also has a low-level binding affinity for phosphate and hypophosphite, whilst HtxB can facilitate phosphite uptake in vivo. However, HtxB does not bind phosphate, thus the HtxBCDE transporter has recently been successfully exploited for biocontainment of genetically modified organisms by phosphite-dependent growth. Here we use a combination of X-ray crystallography, NMR and Microscale Thermophoresis to show that phosphite binding to HtxB depends on the protonation state of the ligand, suggesting that pH may effect the efficiency of phosphite uptake by HtxB in biotechnology applications. PubMed: 31308436DOI: 10.1038/s41598-019-46557-2 PDB entries with the same primary citation |
| Experimental method | X-RAY DIFFRACTION (1.25 Å) |
Structure validation
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