Williams K, Doak T G, Herrick G
Department of Cellular, Viral and Molecular Biology, University of Utah School of Medicine, Salt Lake City, UT 84132.
EMBO J. 1993 Dec;12(12):4593-601. doi: 10.1002/j.1460-2075.1993.tb06148.x.
The 4.1 kbp TBE1 elements of Oxytricha fallax and Oxytricha trifallax are deduced to transpose into a centrisymmetric target, CAnTG, and to duplicate the central AnT. Despite conserved C(A4C4)2 telomeric repeats at their tips, free TBE1s found during macronuclear development are not linear but 4.1 kbp circles closed on one copy of the AnT target duplication. The macronucleus-destined flanks are rejoined to regenerate the target, effecting efficient and precise somatic reversion of the germline transpositional mutation. A model is presented in which transposase catalyzes concerted precise rejoining of the flanks and cyclization of the excised element.
推测嗜热四膜虫和三裂四膜虫的4.1千碱基对TBE1元件可转座到一个中心对称靶标CAnTG中，并复制中心的AnT。尽管其末端存在保守的C(A4C4)2端粒重复序列，但在大核发育过程中发现的游离TBE1不是线性的，而是在AnT靶标重复序列的一个拷贝上封闭形成的4.1千碱基对环状结构。 destined for the macronucleus侧翼重新连接以再生靶标，实现种系转座突变的高效精确体细胞回复。提出了一个模型，其中转座酶催化侧翼的协同精确重新连接和切除元件的环化。
