CDNA SEQUENCES FOR 4 SNAKE-VENOM METALLOPROTEINASES - STRUCTURE, CLASSIFICATION, AND THEIR RELATIONSHIP TO MAMMALIAN REPRODUCTIVE PROTEINS
CDNA SEQUENCES FOR 4 SNAKE-VENOM METALLOPROTEINASES - STRUCTURE, CLASSIFICATION, AND THEIR RELATIONSHIP TO MAMMALIAN REPRODUCTIVE PROTEINS
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DOI：
10.1006/abbi.1994.1026
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发表时间：
1994-01-01
影响因子：
3.9
通讯作者：
FOX, JW
中科院分区：
文献类型：
--
作者：
HITE, LA;JIA, LG;FOX, JW
本文报道了响尾蛇毒出血性金属蛋白酶的4个新的cDNA序列，即出血性毒素a、B、c和d。比较翻译的开放阅读框架的成熟蛋白质序列的翻译后加工的氨基和羧基末端提供了证据。这种比较也是根据这些前体的不同大小建立新的分类系统的基础。酶原区的蛋白质序列支持半胱氨酸开关型维持潜伏期机制的假设。讨论了活性中心锌离子周围的配位几何构型。这些毒液金属蛋白酶和哺乳动物生殖蛋白家族之间的关系也得到了这些序列的支持。最大的蛋白酶，出血毒素a的羧基末端结构域的半胱氨酸模式，比较其他毒液蛋白酶和哺乳动物蛋白质，既表现出惊人的相似性和微妙的差异。这些出血性毒素似乎是由一个更大的祖先的缺失和随后的分歧造成的，它们可能与上述哺乳动物生殖蛋白共享。
Presented here are four new cDNA sequences for hemorrhagic metalloproteinases fromCrotalus atroxvenom, hemorrhagic toxins a, b, c, and d. Comparison of the translated open reading frames to the mature protein sequences gives evidence for post-translational processing at both the amino and carboxyl termini. This comparison is also the basis for a new classification system for these precursors, based on their different sizes. Protein sequences in the zymogen region support the hypothesis of a cysteine-switch type mechanism of maintaining latency. The coordination geometry around the active site zinc ion is discussed. The relationship between these venom metalloproteinases and a family of mammalian reproductive proteins is also supported by these sequences. The cysteine pattern of the carboxyl-terminal domain of the largest proteinase, hemorrhagic toxin a, is compared to other venom proteinases and to the mammalian proteins, showing both striking similarities and subtle differences. It would appear that these hemorrhagic toxins have resulted from deletions and subsequent divergence from a larger ancestor, one they may have shared with the aforementioned mammalian reproductive proteins.