位點特異性重組

位點特異性重組(Site-specific recombination)是生物基因重組的一種機制,即兩段具有一定同源序列DNA發生重組[1][2][3],此過程中兩段DNA序列會發先發生聯會,位點特異性重組酶英语Recombinase(SSR)會與DNA結合,切割兩段DNA後促進酯交換反應,使一段DNA與另一段DNA連接-而形成霍利迪交叉,再進行第二次切割而得到重組過的兩段DNA[4][5]。重組酶可分為酪胺酸重組酶(如Cre重組酶英语Cre recombinaseFLP重組酶英语FLP-FRT recombination)與絲胺酸重組酶(如γδ解離酶Tn3解離酶英语Tn3 transposon)兩大類,兩者結構與詳細反應機理均不同[6][7],前者僅分別切割兩段DNA的一股,後者則將兩段共4股DNA都切割[8]

酪胺酸重組酶催化位點特異性重組的機制,上方為傳統觀點,下方為較新研究的觀點
絲胺酸重組酶催化位點特異性重組的機制,四股DNA均被切割

位點特異性重組的特異性很高[9],在DNA複製可動遺傳因子插入等過程中會發生[10],也被用作基因工程的一項技術[11]。此重組依重複片段的排列狀況可能有整合、切除與倒位三種結果,兩段不同DNA間的位點特異性重組可造成一段DNA被整合進另一段DNA中,同DNA中兩段同向序列的位點特異性重組可造成中間的序列被移除,而兩段反向序列的位點特異性重組則可造成中間序列倒位[12]

參見编辑

參考文獻编辑

  1. ^ Bode, J; Schlake, T; asadasasada Iber, M; Schuebeler, D; Seibler, J; Snezhkov, E; Nikolaev, L. The transgeneticist's toolbox: novel methods for the targeted modification of eukaryotic genomes. Biol. Chem. 2000, 381 (9–10): 801–813. PMID 11076013. doi:10.1515/BC.2000.103. 
  2. ^ Kolb, A.F. Genome Engineering Using Site-Specific Recombinases. Cloning & Stem Cells. 2002, 4 (1): 65–80. PMID 12006158. doi:10.1089/153623002753632066. 
  3. ^ Coates, C.J.; Kaminski, JM; Summers, JB; Segal, DJ; Miller, AD; Kolb, AF. Site-directed genome modification: derivatives of BAL-modifying enzymes as targeting tools (PDF). Trends in Biotechnology. 2005, 23 (8): 407–19. PMID 15993503. doi:10.1016/j.tibtech.2005.06.009. (原始内容 (PDF)存档于2006-08-29). 
  4. ^ Van Duyne, G.D. A structural view of tyrosine recombinase site-specific recombination. Mobile DNA II. ASM Press. 2002: 93–117. 
  5. ^ Holliday, R. A mechanism for gene conversion in fungi (PDF). Genetics Research. 1964, 5 (2): 282–304. doi:10.1017/S0016672300001233. 
  6. ^ Abdel-Meguid, S.S.; Grindley, N.D.; Templeton, N.S.; Steitz, T.A. Cleavage of the site-specific recombination protein gamma delta resolvase: the smaller of two fragments binds DNA specifically. Proc. Natl. Acad. Sci. U.S.A. April 1984, 81 (7): 2001–5. Bibcode:1984PNAS...81.2001A. PMC 345424 . PMID 6326096. doi:10.1073/pnas.81.7.2001. 
  7. ^ Yang, W.; Steitz, T.A. Crystal structure of the site-specific recombinase gamma delta resolvase complexed with a 34 bp cleavage site. Cell. 1995, 82 (2): 193–207. PMID 7628011. doi:10.1016/0092-8674(95)90307-0. 
  8. ^ Stark, W.M.; Boocock, M.R.; Sherratt, DJ. Catalysis by site-specific recombinases. Trends in Genetics. 1992, 8 (12): 432–9. PMID 1337225. doi:10.1016/0168-9525(92)90327-Z. 
  9. ^ Sauer, B. Inducible Gene Targeting in Mice Using the Cre/loxSystem (PDF). Methods. 1998, 14 (4): 381–92. PMID 9608509. doi:10.1006/meth.1998.0593. (原始内容 (PDF)存档于2011-06-11). 
  10. ^ Nash, H. A. (1996). Site-specific recombination: integration, excision, resolution, and inversion of defined DNA segments. Escherichia coli and Salmonella: cellular and molecular biology, 2, pp. 2363–2376.
  11. ^ Akopian, A.; Stark, W.M. Site-Specific DNA Recombinases as Instruments for Genomic Surgery. Advances in Genetics 55. 2005: 1–23. ISBN 978-0-12-017655-7. PMID 16291210. doi:10.1016/S0065-2660(05)55001-6. 
  12. ^ Grindley ND, Whiteson KL, Rice PA. Mechanisms of site-specific recombination.. Annu Rev Biochem. 2006, 75: 567–605. PMID 16756503. doi:10.1146/annurev.biochem.73.011303.073908.