THE SEGMENT IDENTITY FUNCTIONS OF ULTRABITHORAX ARE CONTAINED WITHIN ITS HOMEO DOMAIN AND CARBOXY-TERMINAL SEQUENCES
THE SEGMENT IDENTITY FUNCTIONS OF ULTRABITHORAX ARE CONTAINED WITHIN ITS HOMEO DOMAIN AND CARBOXY-TERMINAL SEQUENCES
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DOI：
10.1101/gad.7.5.796
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发表时间：
1993-05-01
影响因子：
10.5
通讯作者：
MANN, RS
中科院分区：
文献类型：
--
作者：
CHAN, SK;MANN, RS
利用体内片段鉴定方法，研究了两种果蝇同源选择蛋白Ultrabithorax （Ubx）和Antennapedia （Antp）的结构差异。Ubx和Antp至少有两个独立的部分促成了它们的功能特异性：(1)它们的同源结构域和(2)它们的同源结构域的羧基末端残基（c -tail）。在没有任何c尾的情况下，5个同源结构域氨基酸的差异足以区分Ubx和Antp的功能。其中两个位于同源结构域的氨基末端，可以直接与DNA接触。三维模型表明，其他3个同源结构域残基和c -尾不太可能与DNA接触。此外，我们证明了用于测量Ubx和Antp的区段识别功能的分析是独立于任何同型选择基因通常活跃在胸和腹段。因此，该实验很可能测量了许多下游靶基因的协调调节。至少一个Ubx靶基因Distal-less证实了这一预期。
Using an in vivo assay for segment identity, the structural differences that distinguish two Drosophila homeotic selector proteins, Ultrabithorax (Ubx) and Antennapedia (Antp), have been investigated. There are at least two independent parts of Ubx and Antp that contribute to their functional specificities: (1) their homeo domains and (2) residues carboxy-terminal to their homeo domains (C-tails). In the absence of any C-tail, differences in 5 homeo domain amino acids are sufficient to distinguish between the functions of Ubx and Antp. Two of these are at the amino terminus of the homeo domain and could contact DNA directly. A three dimensional model suggests that the other 3 homeo domain residues and the C-tails are unlikely to contact DNA. In addition, we demonstrate that the assay used to measure the segment identity functions of Ubx and Antp is independent of any homeotic selector gene normally active in thoracic and abdominal segments. Therefore, it is likely that this assay measures the coordinate regulation of many downstream target genes. This expectation is confirmed for at least one Ubx target gene, Distal-less.