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Ribosomal DNA

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DNA sequence that codes for ribosomal RNA


Ribosomal DNA is the sequence of DNA that codes for ribosomal RNA. In eukaryotes, the ribosomal DNA contains a tandem repeat of a unit segment, an operon, composed of NTS, ETS, 18S, ITS1, 5.8S, ITS2, and 28S tracts, as well as a gene coding for 5S ribosomal RNA.1

Ribosomal RNA is a specialized RNA molecule present in the ribosome. The ribosomal RNA does not carry the code in making proteins. Nevertheless, it constitutes the predominant material within the ribosome. In eukaryotes, in particular, the ribosomes consist of one or three large rRNA molecules. The ribosomal RNAs form two subunits, i.e. large subunit and small subunit. The large subunit serves as a ribozyme. Apart from the ribosomal RNA, ribosomes also have proteins (about 40% by weight).

Ribosomes are cytoplasmic particles essential in protein synthesis. It builds proteins according to the genetic sequence held within the messenger RNA. Using the mRNA as a template, the ribosome traverses each codon, pairing it with the appropriate amino acid. This is done through interacting with transfer RNA (tRNA) containing a complementary anticodon on one end and the appropriate amino acid on the other.

Abbreviation / Acronym: rDNA


  • ribosomal deoxyribonucleic acid

See also:

1 Ribosomal DNA. Retrieved from [1].