5'-Terminal 7-methylguanosine in eukaryotic mRNA is required for translation.

Unmethylated reovirus and VSV mRNAs are specifically methylated to form 5'-terminal structures of the type, m-7-G(5')ppp(5')N by protein synthesising extracts prepared from wheat germ and mouse L cells. Reticulocyte mRNA also contains 5'-terminal m-7-G. MRNAs having 5'-terminal m-7-G stimulate protein synthesis in vitro. Removal of m-7-G by beta-elimination abolishes translation of the mRNAs.     

Insect chitinase and chitinase-like proteins

Insect chitinases belong to family 18 glycosylhydrolases that hydrolyze chitin by an endo-type of cleavage while retaining the anomeric β-(1→4) configuration of products. There are multiple genes encoding chitinases and chitinase-like proteins in all insect species studied using bioinformatics searches. These chitinases differ in size, domain organization, physical, chemical and enzymatic properties, and in patterns of their expression during development. There are also differences in tissue specificity of expression. Based on a phylogenetic analysis, insect chitinases and chitinase-like proteins have been classified into several different groups. Results of RNA interference experiments demonstrate that at least some of these chitinases belonging to different groups serve non-redundant functions and are essential for insect survival, molting or development. Chitinases have been utilized for biological control of insect pests on transgenic plants either alone or in combination with other insecticidal proteins. Specific chitinases may prove to be useful as biocontrol agents and/or as vaccines.