Lambda N, a small basic protein of the arginine-rich motif (ARM) family of RNA binding proteins, binds to a 15-nucleotide (nt) stem-loop called BOXB. (We will capitalize the names of sites in RNA and italicize the names of the corresponding DNA sequences; e.g., BOXB and boxB.) boxB is found twice in the lambda chromosome, once in each of the two early operons. It is close to the start point of the PL operon transcript and just downstream of the first translated gene of the PR operon.