| RNA caps | Compounds with the general structure 7-methyl-5'-guanosine triphosphate-5'-x which modify the 5' end of eukaryotic cellular and viral messenger RNA and some heterogeneous nuclear rnas. These compounds, which are positively charged, protect the above specified rnas at their termini against attack by phosphatases and other nucleases and promote mRNA function at the level of initiation of translation. Analogs of the RNA caps (RNA cap analogs), which lack the positive charge, inhibit the initiation of protein synthesis. (12 Dec 1998) |
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| dental caps | <veterinary> Deciduous cheek teeth in the horse which remain attached to erupting permanent teeth. (05 Mar 2000) |