| Mouse vimentin : structural relationship to fos , jun , CREB and tpr . ^^^ Specifically , 50 70 % structural similarity was observed between the basic domain of the DNA binding region of the nuclear proto oncogene products c fos and its related antigen fra 1 , c jun and the cAMP responsive DNA binding protein CREB , with part of the N terminal half region of helix 1b of vimentin . ^^^ When the leucine zipper domains of all these proteins were compared to vimentin , at least two different regions of similarity in the vimentin molecule were found reaching up to 53 % for jun , 60 % for fos , and 76 % for CREB . ^^^ |