COTRANSLATIONAL PROCESSING AND PROTEIN-TURNOVER IN EUKARYOTIC CELLS
COTRANSLATIONAL PROCESSING AND PROTEIN-TURNOVER IN EUKARYOTIC CELLS
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DOI：
10.1021/bi00421a001
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发表时间：
1988-10-18
期刊：
影响因子：
2.9
通讯作者：
BRADSHAW, RA
中科院分区：
文献类型：
--
作者：
ARFIN, SM;BRADSHAW, RA
1987;米勒等人，1987年）。NAT和MAP的部分纯化制剂的初步表征表明这两种酶都是大的多聚体分子。此外，大鼠肝脏NAT制剂显示出非凡的不稳定性，如已经注意到的来自其他来源的NAT制剂（Driessen等人，1985），其仅被EDTA和脱氧胆酸盐部分稳定（Yamada等人，1987年）。从蛋白质序列数据库中发现的密切相关的、直接确定的结构的检查中推测了两种酶的特异性（Wavesson等人，1985; Driessen等人，1985;谢尔曼等人，1986）和主要在酵母中的许多突变蛋白的检测（Tsunasawa等人，1985年）。在数据允许的范围内，这些分析表明MAP被相邻的带电或大体积残基抑制（Burstein & Schechter，1978;谢尔曼等人，1986），并且N“-乙酰基倾向于被添加到具有相对小侧链的末端氨基酸上，只有少数例外（Wavesonetal.，1985; Bloemendal，1977）。主要指定残基似乎是倒数第二个氨基酸（在去除引发剂甲硫氨酸的情况下，其变为N-末端）。然而，计算机分析还表明，在距离氨基末端远至40个残基的区域中可以发现另外的特定影响（Wavesson等人，1985; Augen& Wold，1986）。
1987; Miller et al., 1987). Preliminary characterization of partially purified preparations of NAT and MAP suggests both enzymes are large, multimeric molecules. In addition, rat liver NAT preparations display extraordinary lability, as has been noted for NAT preparations from other sources(Driessen et al., 1985), that is only partially stabilized by EDTA and de-oxycholate (Yamada et al., 1987). The specificity of both enzymes has been surmised from an examination of the germane, directly determined structures found in the protein sequence data base (Persson et al., 1985; Driessen et al., 1985; Sherman et al., 1986) and by an exam-ination of a number of mutant proteins, primarily in yeast (Tsunasawa et al., 1985). These analyses, insofar as the data allow, suggest that MAP is inhibited by an adjacent charged or bulky residue (Burstein & Schechter, 1978; Sherman et al., 1986) and that iV “-acetyl groups tend to be added, with only a few exceptions, to terminal amino acids with relatively small side chains (Persson et al., 1985; Bloemendal, 1977). The primary specifying residue appears to be the penultimate amino acid (which becomes the N-terminal in instances where the initiator methionine is removed). However, computer analyses have also suggested that additional specifying influences may be found in regions as far as 40 residues from the amino terminus (Persson et al., 1985; Augen& Wold, 1986).