Summary for 5Y8A
| Entry DOI | 10.2210/pdb5y8a/pdb |
| Related | 5GIZ 5GJ3 |
| Descriptor | Putative hemin transport system, substrate-binding protein, PROTOPORPHYRIN IX CONTAINING FE, CALCIUM ION, ... (4 entities in total) |
| Functional Keywords | metal transport, transport protein |
| Biological source | Burkholderia cenocepacia (strain ATCC BAA-245 / DSM 16553 / LMG 16656 / NCTC 13227 / J2315 / CF5610) |
| Total number of polymer chains | 2 |
| Total formula weight | 58538.08 |
| Authors | Nakamura, N.,Naoe, Y.,Rahman, M.M.,Shiro, Y.,Sugimoto, H. (deposition date: 2017-08-20, release date: 2017-10-11, Last modification date: 2023-11-22) |
| Primary citation | Naoe, Y.,Nakamura, N.,Rahman, M.M.,Tosha, T.,Nagatoishi, S.,Tsumoto, K.,Shiro, Y.,Sugimoto, H. Structural basis for binding and transfer of heme in bacterial heme-acquisition systems Proteins, 85:2217-2230, 2017 Cited by PubMed Abstract: Periplasmic heme-binding proteins (PBPs) in Gram-negative bacteria are components of the heme acquisition system. These proteins shuttle heme across the periplasmic space from outer membrane receptors to ATP-binding cassette (ABC) heme importers located in the inner-membrane. In the present study, we characterized the structures of PBPs found in the pathogen Burkholderia cenocepacia (BhuT) and in the thermophile Roseiflexus sp. RS-1 (RhuT) in the heme-free and heme-bound forms. The conserved motif, in which a well-conserved Tyr interacts with the nearby Arg coordinates on heme iron, was observed in both PBPs. The heme was recognized by its surroundings in a variety of manners including hydrophobic interactions and hydrogen bonds, which was confirmed by isothermal titration calorimetry. Furthermore, this study of 3 forms of BhuT allowed the first structural comparison and showed that the heme-binding cleft of BhuT adopts an "open" state in the heme-free and 2-heme-bound forms, and a "closed" state in the one-heme-bound form with unique conformational changes. Such a conformational change might adjust the interaction of the heme(s) with the residues in PBP and facilitate the transfer of the heme into the translocation channel of the importer. PubMed: 28913898DOI: 10.1002/prot.25386 PDB entries with the same primary citation |
| Experimental method | X-RAY DIFFRACTION (2.001 Å) |
Structure validation
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