INVITRO BIOSYNTHESIS OF DIPHTHAMIDE, STUDIED WITH MUTANT CHINESE-HAMSTER OVARY CELLS RESISTANT TO DIPHTHERIA-TOXIN
INVITRO BIOSYNTHESIS OF DIPHTHAMIDE, STUDIED WITH MUTANT CHINESE-HAMSTER OVARY CELLS RESISTANT TO DIPHTHERIA-TOXIN
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DOI：
10.1128/mcb.4.4.642
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发表时间：
1984-01-01
影响因子：
5.3
通讯作者：
MOEHRING, JM
中科院分区：
文献类型：
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作者：
MOEHRING, TJ;DANLEY, DE;MOEHRING, JM
白喉酰胺是一种独特的氨基酸，是组氨酸的翻译后衍生物，存在于蛋白质合成延伸因子2中，位于白喉毒素催化的延伸因子2的ADP-核糖基化位点。在生物合成中的步骤，研究了与突变体的中国仓鼠卵巢细胞，在不同的步骤中改变了这个复杂的翻译后修饰。该修饰至少需要3个步骤，其中2个在体外完成。鉴定了将甲基从S-腺苷甲硫氨酸转移到非甲基化形式的白喉（白喉的脱酰胺形式）的甲基转移酶活性，并初步鉴定了参与从白喉生物合成白喉的ATP依赖性合成酶活性。计算结果与邻苯二甲酰胺的结构建议值雅阁。
Diphthamide, a unique amino acid, is a post-translational derivative of histidine that exists in protein synthesis elongation factor 2 at the site of diphtheria toxin-catalyzed ADP-ribosylation of elongation factor 2. Steps in the biosynthesis of diphthamide were investigated with mutants of Chinese hamster ovary cells that were altered in different steps of this complex post-translational modification. This modification requires a minimum of 3 steps, 2 of which were accomplished in vitro. A methyltransferase activity that transfers methyl groups from S-adenosyl methionine to an unmethylated form of diphthine (the deamidated form of diphthamide) was identified, and an ATP-dependent synthetase activity involved in the biosynthesis of diphthamide from diphthine was tentatively identified. The results are in accord with the proposed structure of diphthamide.