Chemistry and Biology of Self-Cleaving Ribozymes.
Self-cleaving ribozymes were discovered 30 years ago, but their biological distribution and catalytic mechanisms are only beginning to be defined. Each ribozyme family is defined by a distinct structure, with unique active sites accelerating the same transesterification reaction across the families. Biochemical studies show that general acid-base catalysis is the most common mechanism of self-cleavage, but metal ions and metabolites can be used as cofactors. Ribozymes have been discovered in highly diverse genomic contexts throughout nature, from viroids to vertebrates. Their biological roles include self-scission during rolling-circle replication of RNA genomes, co-transcriptional processing of retrotransposons, and metabolite-dependent gene expression regulation in bacteria. Other examples, including highly conserved mammalian ribozymes, suggest that many new biological roles are yet to be discovered.
Department of Molecular Biology and Biochemistry, University of California, Irvine, CA, USA.
Randi M
RM
Jimenez
Department of Molecular Biology and Biochemistry, University of California, Irvine, CA, USA.
Julio A
JA
Polanco
Department of Molecular Biology and Biochemistry, University of California, Irvine, CA, USA; Department of Pharmaceutical Sciences, University of California, Irvine, CA, USA; Department of Chemistry, University of California, Irvine, CA, USA. Electronic address: aluptak@uci.edu.
Andrej
A
Lupták
D000818:Animals; D006868:Hydrolysis; D016337:RNA, Catalytic / Q000378:metabolism*
D016337:RNA, Catalytic
aptazymes; retrotransposon; riboregulation; riboswitch; ribozyme; self-scission