Homing endonuclease structure and function

作者：Barry Stoddard · 发表于：Quarterly Reviews of Biophysics · 年份：2005 · DOI：10.1017/s0033583505004063 · 被引用次数：465 · 研究领域：RNA and protein synthesis mechanisms、CRISPR and Genetic Engineering、Bacterial Genetics and Biotechnology

Homing endonucleases are encoded by open reading frames that are embedded within group I, group II and archael introns, as well as inteins (intervening sequences that are spliced and excised post-translationally). These enzymes initiate transfer of those elements (and themselves) by generating strand breaks in cognate alleles that lack the intervening sequence, as well as in additional ectopic sites that broaden the range of intron and intein mobility. Homing endonucleases can be divided into several unique families that are remarkable in several respects: they display extremely high DNA-binding specificities which arise from long DNA target sites (14-40 bp), they are tolerant of a variety of sequence variations in these sites, and they display disparate DNA cleavage mechanisms. A significant number of homing endonucleases also act as maturases (highly specific cofactors for the RNA splicing reactions of their cognate introns). Of the known homing group I endonuclease families, two (HNH and His-Cys box enzymes) appear to be diverged from a common ancestral nuclease. While crystal structures of several representatives of the LAGLIDADG endonuclease family have been determined, only structures of single members of the HNH (I-HmuI), His-Cys box (I-PpoI) and GIY-YIG (I-TevI) families have been elucidated. These studies provide an important source of information for structure-function relationships in those families, and are the centerpiece of this review. Finally, homing endonucle...