a tandemly repeated dna hexanucleotide sequence , 5 ' c-c-c-c-a-a3 ' , that occurs at the termini of extrachromosomal dna molecules coding for rrna ( rdna ) in tetrahymena macronuclei was examined to determine whether it is packaged as nucleosomes .
C0012854
dna molecules
C0012933
rdna