guanosine(15) in tRNA + 7-cyano-7-deazaguanine = 7-cyano-7-carbaguanosine(15) in tRNA + guanine
guanosine(15) in trna + 7-cyano-7-deazaguanine = 7-cyano-7-carbaguanosine(15) in trna + guanine
"tRNA-guanine(15) transglycosylase"
"trna-guanine(15) transglycosylase"