1S57

crystal structure of nucleoside diphosphate kinase 2 from Arabidopsis

Summary for 1S57

• Entry DOI: 10.2210/pdb1s57/pdb
• Related: 1S59
• Descriptor: Nucleoside diphosphate kinase II, SULFATE ION, 4-(2-HYDROXYETHYL)-1-PIPERAZINE ETHANESULFONIC ACID, ... (4 entities in total)
• Functional Keywords: transferase, kinase
• Biological source: Arabidopsis thaliana (thale cress)
• Cellular location: Plastid, chloroplast: O64903
• Total number of polymer chains: 6
• Total formula weight: 105648.76

Authors

Im, Y.J.,Kim, J.-I.,Shen, Y.,Na, Y.,Han, Y.-J.,Kim, S.-H.,Song, P.-S.,Eom, S.H. (deposition date: 2004-01-20, release date: 2004-11-30, Last modification date: 2023-10-25)

Primary citation

Im, Y.J.,Kim, J.-I.,Shen, Y.,Na, Y.,Han, Y.-J.,Kim, S.-H.,Song, P.-S.,Eom, S.H.
Structural analysis of Arabidopsis thaliana nucleoside diphosphate kinase-2 for phytochrome-mediated light signaling
J.Mol.Biol., 343:659-670, 2004

PubMed Abstract: In plants, nucleoside diphosphate kinases (NDPKs) play a key role in the signaling of both stress and light. However, little is known about the structural elements involved in their function. Of the three NDPKs (NDPK1-NDPK3) expressed in Arabidopsis thaliana, NDPK2 is involved in phytochrome-mediated signal transduction. In this study, we found that the binding of dNDP or NTP to NDPK2 strengthens the interaction significantly between activated phytochrome and NDPK2. To better understand the structural basis of the phytochrome-NDPK2 interaction, we determined the X-ray structures of NDPK1, NDPK2, and dGTP-bound NDPK2 from A.thaliana at 1.8A, 2.6A, and 2.4A, respectively. The structures showed that nucleotide binding caused a slight conformational change in NDPK2 that was confined to helices alphaA and alpha2. This suggests that the presence of nucleotide in the active site and/or the evoked conformational change contributes to the recognition of NDPK2 by activated phytochrome. In vitro binding assays showed that only NDPK2 interacted specifically with the phytochrome and the C-terminal regulatory domain of phytochrome is involved in the interaction. A domain swap experiment between NDPK1 and NDPK2 showed that the variable C-terminal region of NDPK2 is important for the activation by phytochrome. The structure of Arabidopsis NDPK1 and NDPK2 showed that the isoforms share common electrostatic surfaces at the nucleotide-binding site, but the variable C-terminal regions have distinct electrostatic charge distributions. These findings suggest that the binding of nucleotide to NDPK2 plays a regulatory role in phytochrome signaling and that the C-terminal extension of NDPK2 provides a potential binding surface for the specific interaction with phytochromes.

PubMed: 15465053
DOI: 10.1016/j.jmb.2004.08.054

Experimental method

X-RAY DIFFRACTION (1.8 Å)