Assembly of recently translated full-length and C-terminal truncated human gamma-globin chains with a pool of alpha-globin chains to form Hb F in a cell-free system.
Assembly of recently translated full-length and C-terminal truncated human gamma-globin chains with a pool of alpha-globin chains to form Hb F in a cell-free system.
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将最近翻译的全长和 C 端截短的人 γ 珠蛋白链与一组 α 珠蛋白链组装在一起，在无细胞系统中形成 Hb F。
DOI：
10.1016/j.abb.2007.02.030
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发表时间：
2007
影响因子：
3.9
通讯作者：
Surrey,Saul
中科院分区：
文献类型：
--
作者：
Adachi,Kazuhiko;Zhao,Yi;Lakka,Vinaysagar;Weiss,MitchellJ;Surrey,Saul
在无细胞转录/翻译系统中评估α-珠蛋白与翻译的全长和C-末端截短的人γ-珠蛋白组装以形成Hb F。多核糖体的结构分析表明，保留在多核糖体上的两个氨基酸C端截短的γ链只有在嘌呤霉素诱导链释放后才能与未标记的完整α链组装。在不添加嘌呤霉素的情况下，由在翻译终止位点含有终止密码子的载体编码的两个氨基酸C末端截短的γ链从多聚核糖体释放并与α链组装，而从γ链羧基末端去除11个或更多个氨基酸抑制与α链的组装。这些结果表明，HC-和H-螺旋γ链区域的氨基酸，包括翻译的γ链C-末端的氨基酸135-144，在与α链的组装中起关键作用，并且组装发生在翻译的γ链从核糖体隧道退出并从多聚体释放后不久，从而阻止稳定的γ 2同源二聚体形成。
Assembly of α-globin with translated, full-length and C-terminal truncated human γ-globin to form Hb F was assessed in a cell-free transcription/translation system. Polysome profiles showed two amino acid C-terminal-truncated γ-chains retained on polysomes can assemble with unlabeled holo α-chains only after puromycin-induced chain release. Two amino acid C-terminal truncated γ-chains encoded from vectors containing a stop codon at the translation termination site were released from polysomes and assembled with α-chains in the absence of puromycin addition, while removal of 11 or more amino acids from the γ-chain carboxy-terminus inhibited assembly with α-chains. These results suggest that amino acids in the HC- and H-helix γ-chain regions including amino acids 135–144 at the C-terminus in the translated γ-chains play a key role in assembly with α-chains, and that assembly occurs soon after exit of translated γ-chains from the ribosome tunnel and release from polysomes thereby preventing stable γ2homo-dimer formation.