Components involved in RNA–protein interaction at the 3 untranslated region of rbcL mRNA of Populus deltoides

RNA–protein interactions occurring at the 3 untranslated region (3 UTR) of the mRNA of rbcL gene from Populus deltoides have been examined. The 3 UTR of rbcL gene in P. deltoides is highly AT rich and contains invert repeat (IR) sequences capable of forming two stem-loops. Gel mobility shift assays followed by SDS–PAGE analysis revealed that the 3 IR-RNA region interacts with a set of proteins having molecular weights between 66 and 26 kDa. The protein complex protected an approximately 82-nucleotide segment of 3 UTR of rbcL mRNA when treated with RNase T1. An internal competition assay using variable lengths of the rbcL 3 UTR indicated that the RNaseT1 protected segment included both stem-loops and a few sequences downstream including a conserved AU rich box. © 2004 Elsevier B.V. All rights reserved.