The landscape of cytokinin binding by a plant nodulin.Ruszkowski, M., Szpotkowski, K., Sikorski, M., Jaskolski, M.
(2013) Acta Crystallogr.,Sect.D 69: 2365-2380
- PubMed: 24311578
- DOI: 10.1107/S0907444913021975
- Primary Citation of Related Structures:
- Also Cited By: 5I8F, 5MXW, 5MXB, 4PSB, 4Q0K
- PubMed Abstract:
- Crystal structure of Vigna radiata cytokinin-specific binding protein in complex with zeatin.
Pasternak, O.,Bujacz, G.D.,Fujimoto, Y.,Hashimoto, Y.,Jelen, F.,Otlewski, J.,Sikorski, M.M.,Jaskolski, M.
(2006) Plant Cell 18: 2622
- Structural and functional aspects of PR-10 proteins.
Fernandes, H.,Michalska, K.,Sikorski, M.,Jaskolski, M.
(2013) Febs J. 280: 1169
- Cytokinin-induced structural adaptability of a Lupinus luteus PR-10 protein.
Fernandes, H.,Bujacz, A.,Bujacz, G.,Jelen, F.,Jasinski, M.,Kachlicki, P.,Otlewski, J.,Sikorski, M.M.,Jaskolski, M.
(2009) Febs J. 276: 1596
- Symbiosis-specific expression of two Medicago truncatula nodulin genes, MtN1 and MtN13, encoding products homologous to plant defense proteins.
Gamas, P.,de Billy, F.,Truchet, G.
(1998) Mol.Plant Microbe Interact. 11: 393
- Lupinus luteus pathogenesis-related protein as a reservoir for cytokinin.
Fernandes, H.,Pasternak, O.,Bujacz, G.,Bujacz, A.,Sikorski, M.M.,Jaskolski, M.
(2008) J.Mol.Biol. 378: 1040
Nodulation is an extraordinary symbiotic interaction between leguminous plants and nitrogen-fixing bacteria (rhizobia) that assimilate atmospheric nitrogen (in root nodules) and convert it into compounds suitable for the plant host. A class of plant ...
Nodulation is an extraordinary symbiotic interaction between leguminous plants and nitrogen-fixing bacteria (rhizobia) that assimilate atmospheric nitrogen (in root nodules) and convert it into compounds suitable for the plant host. A class of plant hormones called cytokinins are involved in the nodulation process. In the model legume Medicago truncatula, nodulin 13 (MtN13), which belongs to the pathogenesis-related proteins of class 10 (PR-10), is expressed in the outer cortex of the nodules. In general, PR-10 proteins are small and monomeric and have a characteristic fold with an internal hydrophobic cavity formed between a seven-stranded antiparallel β-sheet and a C-terminal α-helix. Previously, some PR-10 proteins not related to nodulation were found to bind cytokinins such as trans-zeatin. Here, four crystal structures of the MtN13 protein are reported in complexes with several cytokinins, namely trans-zeatin, N6-isopentenyladenine, kinetin and N6-benzyladenine. All four phytohormones are bound in the hydrophobic cavity in the same manner and have excellent definition in the electron-density maps. The binding of the cytokinins appears to be strong and specific and is reinforced by several hydrogen bonds. Although the binding stoichiometry is 1:1, the complex is actually dimeric, with a cytokinin molecule bound in each subunit. The ligand-binding site in each cavity is formed with the participation of a loop element from the other subunit, which plugs the only entrance to the cavity. Interestingly, a homodimer of MtN13 is also formed in solution, as confirmed by small-angle X-ray scattering (SAXS).
Center for Biocrystallographic Research, Institute of Bioorganic Chemistry, Polish Academy of Sciences, Poznan, Poland.