mRNA cap methylation, RNMT-activating mini protein
This family of proteins is found in eukaryotes. Proteins in this family are typically between 102 and 154 amino acids in length. There is a single completely conserved residue D that may be functionally important. RAM is a family of eukaryotic proteins that are an obligate component of the mammalian cap methyltransferase, RNMT (RNA guanine-7 methyltransferase). RAM consists of an N-terminal RNMT-activating domain and a C-terminal RNA-binding domain. Either RAM or RNMT independently have rather weak binding affinity for RNA, but together their RNA affinity is significantly increased. RAM is necessary for efficient cap methylation, maintaining mRNA expression levels, for mRNA translation and for cell viability.