Proteins in the GRAS (GAI, RGA, SCR) family are known as major players in gibberellin (GA) signaling, which regulates various aspects of plant growth and development. Mutation of the SCARECROW (SCR) gene results in a radial pattern defect, loss of a ground tissue layer, in the root. The PAT1 protein is involved in phytochrome A signal transduction. A sequence, structure and evolutionary analysis showed that the GRAS family emerged in bacteria and belongs to the Rossmann-fold, AdoMET (SAM)-dependent methyltransferase superfamily. All bacterial, and a subset of plant GRAS proteins, are predicted to be active and function as small-molecule methylases. Several plant GRAS proteins lack one or more AdoMet (SAM)-binding residues while preserving their substrate-binding residues. Although GRAS proteins are implicated to function as transcriptional factors, the above analysis suggests that they instead might either modify or bind small molecules.