Multiple choice Which of the following DNA repeats encodes a protein containing a leucine zipper motif? SINEs UTR Second ORF First ORF LTRs Reveal answer Fill a bubble to check yourself D Correct answer Explanation The first ORF encodes a RNA-binding protein of 500 amino acid lengths that weighs 40 kDA. This protein contains a leucine zipper motif and functions as a chaperone.