tailieunhanh - Báo cáo y học: " Mobile DNA elements in T4 and related phages"

Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành y học dành cho các bạn tham khảo đề tài: Mobile DNA elements in T4 and related phages | Edgell et al. Virology Journal 2010 7 290 http content 7 1 290 VIROLOGY JOURNAL REVIEW Open Access Mobile DNA elements in T4 and related phages David R Edgell1 Ewan A Gibb1 Marlene Belfort2 Abstract Mobile genetic elements are common inhabitants of virtually every genome where they can exert profound influences on genome structure and function in addition to promoting their own spread within and between genomes. Phage T4 and related phage have long served as a model system for understanding the molecular mechanisms by which a certain class of mobile DNA homing endonucleases promote their spread. Homing endonucleases are site-specific DNA endonucleases that initiate mobility by introducing double-strand breaks at defined positions in genomes lacking the endonuclease gene stimulating repair and recombination pathways that mobilize the endonuclease coding region. In phage T4 homing endonucleases were first discovered as encoded within the self-splicing td nrdB and nrdD introns of T4. Genomic data has revealed that homing endonucleases are extremely widespread in T-even-like phage as evidenced by the astounding fact that 11 of the T4 genome encodes homing endonuclease genes with most of them located outside of self-splicing introns. Detailed studies of the mobile td intron and its encoded endonuclease I-TevI have laid the foundation for genetic biochemical and structural aspects that regulate the mobility process and more recently have provided insights into regulation of homing endonuclease function. Here we summarize the current state of knowledge regarding T4-encoded homing endonucleases with particular emphasis on the td I-TevI model system. We also discuss recent progress in the biology of free-standing endonucleases and present areas of future research for this fascinating class of mobile genetic elements. Introduction In the 20 years since the first review on mobile genetic elements in the T4 genome significant progress has been made with .