True statement about Ribozyme
The substrate for ribozymes is often an RNA molecule, and it may even be pa of the ribozyme itself Ribozymes vary greatly in size. A self-splicing group I intron may have more than 400 nucleotides. The hammerhead ribozyme consists of two RNA strands with only 41 nucleotides in all. As with protein enzymes, the three-dimensional structure of ribozymes is impoant for function. Ribozymes are inactivated by heating above their melting temperature or by addition of denaturing agents or complementary oligonucleotides, which disrupt normal base-pairing patterns. Ribozymes can also be inactivated if essential nucleotides are changed. Example: Hammerhead ribozyme: These segments are called hammerhead ribozymes because their secondary structures are shaped like the head of a hammer. The hammerhead ribozyme is a metalloenzyme; Mg+2 ions are required for activity. The phosphodiester bond at the site of self-cleavage is indicated by an arrow In Tetrahymena, the pre-rRNA molecule contains an intron that is removed by self-splicing (in the presence of guanosine, GMP, GDP or GTP) without the need for involvement of any protein. This was the first ribozyme discovered but many have since been repoed.
RNA molecular that acts catalytically to change itself or another RNA molecule
t-RNA
m-RNA
Ribosome
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