We have isolated clones of an Arabidopsis gene (ROF1, for rotamase FKBP) 
encoding a high molecular weight member of the FK506 binding protein (FKBP) 
family. The deduced amino acid sequence of ROF1 predicts a 551-amino acid, 62 
kDa polypeptide which is 44% identical to human FKBP59 - a 59 kDa FKBP which 
binds to the 90 kDa heat shock protein and is associated with inactive steroid 
hormone receptors. ROF1 contains three FKBP12-like domains in the N-terminal 
portion of the protein (in contrast to two domains in mammalian FKBP59), an 
internal repeat structure associated with protein-protein interactions 
(tetratricopeptide repeats), and a putative calmodulin binding domain near the 
C-terminal region of the protein. No sequences associated with protein 
translocation out of the cytosol were found in ROF1. ROF1 mRNA was found at 
equivalent low levels in light-grown roots, stems, and flowers and at slightly 
higher levels in leaves. The abundance of ROF1 mRNA increased several-fold under 
stress conditions such as wounding or exposure to elevated NaCl levels.