Structure and function of regulatory RNA elements: ribozymes that regulate gene expression.
Since their discovery in the 1980s, it has gradually become apparent that there are several functional classes of naturally occurring ribozymes. These include ribozymes that mediate RNA splicing (the Group I and Group II introns, and possibly the RNA components of the spliceosome), RNA processing ribozymes (RNase P, which cleaves precursor tRNAs and other structural RNA precursors), the peptidyl transferase center of the ribosome, and small, self-cleaving genomic ribozymes (including the hammerhead, hairpin, HDV and VS ribozymes). The most recently discovered functional class of ribozymes include those that are embedded in the untranslated regions of mature mRNAs that regulate the gene's translational expression. These include the prokaryotic glmS ribozyme, a bacterial riboswitch, and a variant of the hammerhead ribozyme, which has been found embedded in mammalian mRNAs. With the discovery of a mammalian riboswitch ribozyme, the question of how an embedded hammerhead ribozyme's switching mechanism works becomes a compelling question. Recent structural results suggest several possibilities.
Center for the Molecular Biology of RNA, Sinsheimer Laboratory, University of California at Santa Cruz, Santa Cruz, CA, USA. wgscott@chemistry.ucsc.edu
William G
WG
Scott
Monika
M
Martick
Young-In
YI
Chi
D000818:Animals; D001483:Base Sequence; D005786:Gene Expression Regulation; D006801:Humans; D008025:Ligases / Q000737:chemistry; D008956:Models, Chemical; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D012313:RNA / Q000737:chemistry / Q000235:genetics*; D016337:RNA, Catalytic / Q000737:chemistry; D050436:Regulatory Elements, Transcriptional; D012270:Ribosomes / Q000737:chemistry / Q000378:metabolism*; D012689:Sequence Homology, Nucleic Acid
D016337:RNA, Catalytic; C427204:hammerhead ribozyme; D012313:RNA; D008025:Ligases