S-adenosylmethionine:tRNA ribosyltransferase-isomerase (EC 2.4.99.17 QueA enzyme queuosine biosynthesis protein QueA) is an enzyme with system name S-adenosyl-L-methionine:7-aminomethyl-7-deazaguanosine ribosyltransferase (ribosyl isomerizing; L-methionine adenine releasing).