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Publication Abstract from PubMed

Ethylene initiates important aspects of plant growth and development through disulfide- linked receptor dimers, located in the endoplasmic reticulum. The receptors feature a small trans-membrane, ethylene binding domain followed by a large cytosolic domain, which serves as a scaffold for the assembly of large molecular weight complexes of different ethylene receptors and other cellular participants of the ethylene signalling pathway. Here we report the crystallographic structures of the ETR1 Catalytic ATP-binding (CA) and the Ethylene response sensor 1 (ERS1) Dimerization Histidine phosphotransfer (DHp) domains and the solution structure of the entire cytosolic domain of ETR1, all from A. thaliana. The isolated dimeric ERS1 DHp domain is asymmetric, the result of different helical bending angles close to the conserved His residue. The structures of the CA, DHp and receiver domains of ethylene receptors and of a homologous, but dissimilar, GAF domain were refined against experimental SAXS data, leading to a structural model of the entire cytosolic domain of the ethylene receptor 1. The model illustrates that the cytosolic domain is shaped like a dumbbell and that the receiver domain is flexible and assumes a different position from those observed in prokaryotic histidine kinases. Furthermore the cytosolic domain of ETR1 plays a key role, interacting with all other receptors and several participants of the ethylene-signalling pathway. Our model, therefore, provides the first step towards a detailed understanding of the molecular mechanics of this important signal transduction process in plants.

Structural Model of the Cytosolic Domain of the Plant Ethylene Receptor 1 (ETR1).,Mayerhofer H, Panneerselvam S, Kaljunen H, Tuukkanen A, Mertens HD, Mueller-Dieckmann J J Biol Chem. 2014 Dec 1. pii: jbc.M114.587667. PMID:25451923^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.