 In E. coli, when attempting to transcribe GAA triplets such as those found in Friedrich’s ataxia, the resulting RNA and template strand can form mismatched loops between different repeats, leading the complementary segment in the coding-strand available to form its own loops which impede replication.Furthermore, replication of DNA and transcription of DNA are not temporally independent; they can occur at the same time and lead to collisions between the replication fork and RNA polymerase complex.In S. cerevisiae, Rrm3 helicase is found at highly transcribed genes in the yeast genome, which is recruited to stabilize a stalling replication fork as described above.