最近，英國愛丁堡大學的科學家發(fā)現(xiàn)了一種酶,，該酶能在基因組的任何位置中“剪切”和“粘貼”(cut-and-paste)“垃圾”DNA,。這項發(fā)現(xiàn)發(fā)表于近期的Cell雜志上，或?qū)⒓铀倩虔煼ǖ陌l(fā)展,。
在基因轉(zhuǎn)座(DNA transposition)過程中,，發(fā)生轉(zhuǎn)移的基因?qū)︵徑幕虻墓δ軙a(chǎn)生重大的影響。在人類基因組中,，抗體基因的重排使得免疫系統(tǒng)更有效地對抗感染,。轉(zhuǎn)移基因的可“剪切”和“粘貼”的性質(zhì)如今已應用于多種科學研究和醫(yī)療應用上。
占人類基因組中近一半的“垃圾”DNA,，之前一直被認為是沒有意義的,。而在該研究中，研究人員發(fā)現(xiàn),，在這種“剪切”和“粘貼”的機制中,，“垃圾”DNA的移動對細胞會產(chǎn)生影響。
研究人員Julia Richardson說,，通過了解這種酶如何引起基因轉(zhuǎn)座,，可以更好調(diào)整和控制該酶。（生物谷Bioon.com）
生物谷國慶專題：新中國生命科學60年
生物谷推薦原始出處：
Cell Volume 138, Issue 6, doi:10.1016/j.cell.2009.07.012
Molecular Architecture of the Mos1 Paired-End Complex: The Structural Basis of DNA Transposition in a Eukaryote
Julia M. Richardson1,Sean D. Colloms2, David J. Finnegan1 and Malcolm D. Walkinshaw1
1School of Biological Sciences, University of Edinburgh, The King's Buildings, Mayfield Road, Edinburgh, EH9 3JR, Scotland
2Xermit, 44 Colchester Drive, Glasgow, G12 0NF, Scotland
A key step in cut-and-paste DNA transposition is the pairing of transposon ends before the element is excised and inserted at a new site in its host genome. Crystallographic analyses of the paired-end complex (PEC) formed from precleaved transposon ends and the transposase of the eukaryotic element Mos1 reveals two parallel ends bound to a dimeric enzyme. The complex has a trans arrangement, with each transposon end recognized by the DNA binding region of one transposase monomer and by the active site of the other monomer. Two additional DNA duplexes in the crystal indicate likely binding sites for flanking DNA. Biochemical data provide support for a model of the target capture complex and identify Arg186 to be critical for target binding. Mixing experiments indicate that a transposase dimer initiates first-strand cleavage and suggest a pathway for PEC formation.
