Crystal structure of a multi-domain immunophilin from Arabidopsis thaliana:: A paradigm for regulation of plant ABC transporters

FKBP42 is a membrane-anchored immunophilin playing a critical role in morphogenesis and development of higher plants. We present the X-ray structure of the cytoplasmic portion of FKBP42 comprising both the FKBP-like domain and the TPR domain at 2.85 angstrom resolution. The data shed light on the probable binding modes of key interaction partners, including HSP90 and two classes of ABC transporters. The resulting models provide a structural background for further investigation of the unique biological properties of this protein. (c) 2006 Elsevier Ltd. All rights reserved.