Myroilysin Is a New Bacterial Member of the M12A Family of Metzincin Metallopeptidases and Is Activated by a Cysteine Switch Mechanism
Myroilysin Is a New Bacterial Member of the M12A Family of Metzincin Metallopeptidases and Is Activated by a Cysteine Switch Mechanism
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Myroilysin 是 Metzincin 金属肽酶 M12A 家族的新细菌成员，由半胱氨酸开关机制激活
DOI：
10.1074/jbc.m116.758110
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发表时间：
2017
影响因子：
4.8
通讯作者：
Wang Weiwu
中科院分区：
文献类型：
--
作者：
Xu Dongqing;Zhou Jiale;Lou Xiangdi;He Jianhua;Ran Tingting;Wang Weiwu
蛋白酶在所有生物体中起着重要作用，也具有重要的工业应用。M12 A家族金属蛋白酶主要在动物界中发现，属于metzincin蛋白酶家族，并作为无活性前体合成。迄今为止，只有从细菌中分离的黄曲霉素和myroilysin被报道为M12 A蛋白酶，而myroilysin的分类由于缺乏结构信息而仍然不清楚。在这里，我们报告的晶体结构pro-myroilysin从bacteriumMyroidessp。cslb8.深活性位点底部的myroilysin前体的催化锌离子与保守基序HEXXXHXXGXXH中的三个组氨酸残基配位;前肽中的半胱氨酸残基与催化锌离子配位并抑制myroilysin活性。结构比较显示，myroilysin与金属蛋白酶的M12 A、M10 A和M10 B家族的成员具有高度相似性。然而，一个独特的“帽”结构顶部的活性位点裂的结构中的前myroilysin，这种“帽”结构不存在于上述结构的亚家族中报道。进一步的基于结构的序列分析显示，myroilysin似乎属于M12 A家族，但pro-myroilysin使用具有独特片段的“半胱氨酸开关”激活机制，包括保守的半胱氨酸残基，而其他报道的M12 A家族蛋白酶使用“天冬氨酸开关”激活机制。因此，我们的研究结果表明，myroilysin是一个新的细菌M12 A家族成员具有特殊的半胱氨酸开关激活机制。我们的研究结果揭示了新的M12 A家族的分类，并可能表明M12家族的分化进化。
Proteases play important roles in all living organisms and also have important industrial applications. Family M12A metalloproteases, mainly found throughout the animal kingdom, belong to the metzincin protease family and are synthesized as inactive precursors. So far, only flavastacin and myroilysin, isolated from bacteria, were reported to be M12A proteases, whereas the classification of myroilysin is still unclear due to the lack of structural information. Here, we report the crystal structures of pro-myroilysin from bacteriumMyroidessp. cslb8. The catalytic zinc ion of pro-myroilysin, at the bottom of a deep active site, is coordinated by three histidine residues in the conserved motif HEXXHXXGXXH; the cysteine residue in the pro-peptide coordinates the catalytic zinc ion and inhibits myroilysin activity. Structure comparisons revealed that myroilysin shares high similarity with the members of the M12A, M10A, and M10B families of metalloproteases. However, a unique “cap” structure tops the active site cleft in the structure of pro-myroilysin, and this “cap” structure does not exist in the above structure-reported subfamilies. Further structure-based sequence analysis revealed that myroilysin appears to belong to the M12A family, but pro-myroilysin uses a “cysteine switch” activation mechanism with a unique segment, including the conserved cysteine residue, whereas other reported M12A family proteases use an “aspartate switch” activation mechanism. Thus, our results suggest that myroilysin is a new bacterial member of the M12A family with an exceptional cysteine switch activation mechanism. Our results shed new light on the classification of the M12A family and may suggest a divergent evolution of the M12 family.