甘蓝型油菜三个单域韧皮环孢素的酶活性和结构特征。

Enzyme activity and structural features of three single-domain phloem cyclophilins from Brassica napus.

机构信息

Universität Hamburg, Institute of Plant Science and Microbiology, Molecular Plant Genetics, Ohnhorststraße 18, 22609, Hamburg, Germany.

Universität Hamburg, Institute of Biochemistry and Molecular Biology, Laboratory for Structural Biology of Infection and Inflammation, c/o DESY, Notkestraße 85, 22603, Hamburg, Germany.

出版信息

Sci Rep. 2019 Jun 27;9(1):9368. doi: 10.1038/s41598-019-45856-y.

DOI:10.1038/s41598-019-45856-y

PMID:31249367

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC6597583/

Abstract

Cyclophilins (CYPs) are a group of ubiquitous prolyl cis/trans isomerases (PPIases). It was shown that plants possess the most diverse CYP families and that these are abundant in the phloem long-distance translocation stream. Since phloem exudate showed PPIase activity, three single-domain CYPs that occur in phloem samples from Brassica napus were characterised on functional and structural levels. It could be shown that they exhibit isomerase activity and that this activity is controlled by a redox regulation mechanism, which has been postulated for divergent CYPs. The structure determination by small-angle X-ray scattering experiments revealed a conserved globular shape. In addition, the high-resolution crystal structure of BnCYP19-1 was resolved and refined to 2.0 Å resolution, and the active sites of related CYPs as well as substrate binding were modelled. The obtained data and results support the hypothesis that single domain phloem CYPs are active phloem PPIases that may function as chaperones.

摘要

细胞色素 P450 （CYPs）是一组普遍存在的脯氨酰顺/反式异构酶（PPIases）。研究表明，植物拥有最多样化的 CYP 家族，这些家族在韧皮部长距离转运流中大量存在。由于韧皮部渗出物显示出 PPIase 活性，因此从油菜中分离出的三种存在于韧皮部样本中的单结构域 CYP 在功能和结构水平上进行了表征。结果表明，它们具有异构酶活性，并且这种活性受到氧化还原调节机制的控制，该机制已被提出用于不同的 CYP。小角度 X 射线散射实验的结构测定揭示了保守的球形形状。此外，还解析并细化了 BnCYP19-1 的高分辨率晶体结构，分辨率为 2.0 Å，并对相关 CYP 的活性位点以及底物结合进行了建模。获得的数据和结果支持这样的假设，即单结构域韧皮部 CYP 是活跃的韧皮部 PPIase，可能作为分子伴侣发挥作用。