6MNI
Structure of the tandem CACHE domain of PscC
Summary for 6MNI
| Entry DOI | 10.2210/pdb6mni/pdb |
| Descriptor | Methyl-accepting chemotaxis protein, PROLINE, GLYCEROL, ... (5 entities in total) |
| Functional Keywords | tandem cache domain, chemoreceptor, ligand complex, pseudomonas syringae pv. actinidiae, pscc, signaling protein |
| Biological source | Pseudomonas syringae pv. actinidiae |
| Total number of polymer chains | 2 |
| Total formula weight | 63597.02 |
| Authors | Johnston, J.M.,Gerth, M.L.,Ehrhardt, M.K.G. (deposition date: 2018-10-01, release date: 2019-10-16, Last modification date: 2023-10-11) |
| Primary citation | Ehrhardt, M.K.G.,Gerth, M.L.,Johnston, J.M. Structure of a double CACHE chemoreceptor ligand-binding domain from Pseudomonas syringae provides insights into the basis of proline recognition. Biochem.Biophys.Res.Commun., 549:194-199, 2021 Cited by PubMed Abstract: Chemotaxis is the process of sensing chemical gradients and navigating towards favourable conditions. Bacterial chemotaxis is mediated by arrays of trans-membrane chemoreceptor proteins. The most common class of chemoreceptors have periplasmic ligand-binding domains (LBDs) that detect extracellular chemical signs and transduce these signals to the downstream chemotaxis machinery. The repertoire of chemoreceptor proteins in a bacterium determines the range of environmental signals to which it can respond. Pseudomonas syringae pv. actinidiae (Psa) is a plant pathogen which causes bacterial canker of kiwifruit (Actinidia sp.). Compared to many other bacteria, Psa has a large number of chemoreceptors encoded in its genome (43) and most of these remain uncharacterized. A previous study identified PscC as a potential chemoreceptor for l-proline and other amino acid ligands. Here, we have characterized the interaction of PscC-LBD with l-proline using a combination of isothermal titration calorimetry (ITC) and X-ray crystallography. ITC confirmed direct binding of l-proline to PscC-LBD with K value of 5.0 μM. We determined the structure of PscC-LBD in complex with l-proline. Our structural analysis showed that PscC-LBD adopts similar double-CACHE fold to several other amino acid chemoreceptors. A comparison of the PscC-LDB to other dCACHE structures highlights residues in the binding cavity which contribute to its ligand specificity. PubMed: 33721671DOI: 10.1016/j.bbrc.2021.02.090 PDB entries with the same primary citation |
| Experimental method | X-RAY DIFFRACTION (1.696 Å) |
Structure validation
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