1TKW
The transient complex of poplar plastocyanin with turnip cytochrome f determined with paramagnetic NMR
Summary for 1TKW
| Entry DOI | 10.2210/pdb1tkw/pdb |
| Related | 1hcz 2pcf 5pcy |
| Descriptor | Plastocyanin A, Cytochrome f, COPPER (II) ION, ... (4 entities in total) |
| Functional Keywords | electron transfer, photosynthesis, paramagnetic, rigid body calculations |
| Biological source | Populus nigra More |
| Cellular location | Plastid, chloroplast thylakoid membrane; Peripheral membrane protein; Lumenal side: P00299 Plastid, chloroplast thylakoid membrane; Single-pass membrane protein: P36438 |
| Total number of polymer chains | 2 |
| Total formula weight | 38721.11 |
| Authors | Lange, C.,Cornvik, T.,Diaz-Moreno, I.,Ubbink, M. (deposition date: 2004-06-09, release date: 2005-05-24, Last modification date: 2022-03-02) |
| Primary citation | Lange, C.,Cornvik, T.,Diaz-Moreno, I.,Ubbink, M. The transient complex of poplar plastocyanin with cytochrome f: effects of ionic strength and pH Biochim.Biophys.Acta, 1707:179-188, 2005 Cited by PubMed Abstract: The orientation of poplar plastocyanin in the complex with turnip cytochrome f has been determined by rigid-body calculations using restraints from paramagnetic NMR measurements. The results show that poplar plastocyanin interacts with cytochrome f with the hydrophobic patch of plastocyanin close to the heme region on cytochrome f and via electrostatic interactions between the charged patches on both proteins. Plastocyanin is tilted relative to the orientation reported for spinach plastocyanin, resulting in a longer distance between iron and copper (13.9 A). With increasing ionic strength, from 0.01 to 0.11 M, all observed chemical-shift changes decrease uniformly, supporting the idea that electrostatic forces contribute to complex formation. There is no indication for a rearrangement of the transient complex in this ionic strength range, contrary to what had been proposed earlier on the basis of kinetic data. By decreasing the pH from pH 7.7 to pH 5.5, the complex is destabilized. This may be attributed to the protonation of the conserved acidic patches or the copper ligand His87 in poplar plastocyanin, which are shown to have similar pK(a) values. The results are interpreted in a two-step model for complex formation. PubMed: 15863096DOI: 10.1016/j.bbabio.2004.12.002 PDB entries with the same primary citation |
| Experimental method | SOLUTION NMR |
Structure validation
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