What are telomerases which plays a role in DNA replication?
DNA dependent DNA polymerase
RNA dependent DNA polymerase
DNA dependent RNA polymerase
RNA dependent RNA polymerase
Telomerase is a RNA dependent DNA polymerase that is expressed in stem cells and most cancer cells, but not in somatic cells. Using an RNA template, telomerase adds GT-rich hexanucleotide repeat sequences ranging from a few hundred (yeast) to several thousand (humans) nucleotides in length to the ends of linear DNA molecules to restore their telomeres to full length. Must know: Telomeres are composed of long strings of GT-rich hexanucleotide repeats that cap the ends of eukaryotic chromosomes. The telomeres at the ends of eukaryotic chromosomes progressively shoen with each cycle of replication. Ref: Kennelly P.J. (2011). Chapter 54. The Biochemistry of Aging. In D.A. Bender, K.M. Botham, P.A. Weil, P.J. Kennelly, R.K. Murray, V.W. Rodwell (Eds), Harper's Illustrated Biochemistry, 29e.