The serC RNA motif is a putative regulatory element found upstream of the serine biosynthesis genes serC-serA in Alphaproteobacteria [16086852]. The serC RNA element consists of two conserved base-paired stems. Formation of the downstream stem of this putative regulatory element will likely sequester the ribosome-binding site and prevent translation initiation. In-line probing of this likely riboswitch motif supports its predicted secondary structure. Testing of metabolites from the serine and related biosynthetic pathways (serine, threonine, PLP, pyridoxal, or pyridoxine) did not reveal a molecular effector of the serC regulatory RNA [16086852].