Exchanging DNA Here, There, and Everywhere

once was. Why do cells devote resources to altering the biochemistry. Many of these chapters are written from meaning of the nucleotide sequences originally speci-a broad historical perspective that is not accessible fied in their genomes? While not providing a simple through the primary literature. The level of detail in some answer to this question, O ¨ hman and Bass succeed in chapters might be more than is appropriate for under-imposing a logical framework on this rapidly developing graduate or graduate coursework. Reference lists ap-field with a clear text and well-chosen illustrations. A pear to be complete through about 1998. Given the rapid variety of mRNA degradation pathways serve to control pace of developments in RNA biochemistry, portions of mRNA abundance and prevent translation of aberrant any book on this subject are bound to be out-of-date transcripts. The chapter on mRNA degradation by almost before publication. The annotated diagrams of Tharun and Parker focuses on the cis-acting sequences nucleotide analogs and tertiary structure motifs and the and protein factors in the major deadenylation-depen-tables of free energy parameters for RNA secondary dent degradation pathway in yeast. Regulated mRNA structure formation along with the illustrations of splic-degradation initiated by sequence-specific endonucle-ing, editing, and degradation pathways will make this ases also is covered briefly. In his chapter on plant viroid book an especially useful resource in RNA biochemistry RNAs, Symons demonstrates how sequence organiza-and molecular biology laboratories. tion and the role of RNA self-cleavage and ligation reactions in the rolling circle replication cycle are becoming Martha J. Fedor better understood for some viroid subgroups. On the Department of Molecular Biology other hand, host-range determinants and mechanisms The Skaggs Institute for Chemical Biology of pathogenicity remain largely mysterious for these Soukup and Strobel present an overview of the struc-and Everywhere tures and the kinetic and catalytic mechanisms of the self-splicing and self-cleaving ribozymes found in nature and several ribozymes that have been identified through Lateral DNA Transfer: Mechanisms in vitro selection. Together, these chapters provide a and Consequences thorough review of the RNA enzymology literature Par ma foi! il y a plus de quarante ans Nature 410, 780–786, 2001) support the notion that RNA que je dis de la prose sans que j'en susse rien, et je nucleobases can participate directly in catalytic chemis-vous suis le plus obligé du monde de m'avoir appris try (Wadkins and Been, Cell. Mol. Life Sci. 59, 112–125, cela. …