Novel requirements in peripheral structures of the extended satellite 2 hammerhead

摘要: A number of RNAs that infect plants self-cleave using a domain called the hammerhead. The consensus plant hammerhead has three base paired stem structures. Stems I and III flank cleaved phosphodiester are connected to II by two unpaired highly conserved sequences. We demonstrated previously satellite 2 transcripts from newt, Notophthalmus viridescens, use modified structure for self-cleavage. Here we show hammerheads with similar modifications occur in species representing additional families salamanders (Ambystoma talpoideum Amphiuma tridactylum). distinctive features include unusually short regions internally looped extensions required cleavage. However, despite strict nucleotide requirement internal loop newt hammerhead, details differ salamanders. An analysis chimeric indicated that, order specific extension be functional, it must compatible other One such region is II, mutational confirmed there sequence and/or structural requirements II.