Molecular structure of human synaptonemal complex protein SYCE1
Molecular structure of human synaptonemal complex protein SYCE1
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DOI：
10.1007/s00412-018-00688-z
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发表时间：
2019-09-01
期刊：
影响因子：
1.6
通讯作者：
Davies, Owen R.
中科院分区：
文献类型：
--
作者：
Dunne, Orla M.;Davies, Owen R.
减数分裂过程中染色体数目的减少对于产生单倍体生殖细胞和生育力是必不可少的。为了实现这一点，同源染色体首先通过蛋白质组装体突触在一起，突触复合体（SC），它允许通过交叉进行遗传交换，随后精确分离同源物。哺乳动物SC由SYCP 1分子的拉链状阵列形成，SYCP 1分子通过在中线中的自组装将同源染色体结合在一起，中线在结构上由中心元件支持。SC中心元件包含5种蛋白质SYCE 1、SYCE 3、SIX 6 OS 1和SYCE 2-TEX 12，它们允许SYCP 1装配沿染色体长度沿着延伸以实现完全突触。在这里，我们报告的结构，人SYCE 1通过解决生物物理方法，包括多角度光散射和小角度X射线散射。SYCE 1的结构核心由蛋白质N-末端一半内的氨基酸25-179形成，其介导SYCE 1二聚化。该α-螺旋芯采用20 nm长的弯曲卷曲螺旋结构，其中两个链以反平行配置布置。这种结构保留在全长SYCE 1中，其中长C-末端采用延伸构象以实现长度超过50 nm的伸长分子。SYCE 1结构与其作为物理支柱的功能相兼容，该物理支柱栓系其他组件以实现SC中心元件的结构稳定性。
The reduction in chromosome number during meiosis is essential for the production of haploid germ cells and thereby fertility. To achieve this, homologous chromosomes are first synapsed together by a protein assembly, the synaptonemal complex (SC), which permits genetic exchange by crossing over and the subsequent accurate segregation of homologues. The mammalian SC is formed of a zipper-like array of SYCP1 molecules that bind together homologous chromosomes through self-assembly in the midline that is structurally supported by the central element. The SC central element contains five proteins-SYCE1, SYCE3, SIX6OS1, and SYCE2-TEX12-that permit SYCP1 assembly to extend along the chromosome length to achieve full synapsis. Here, we report the structure of human SYCE1 through solution biophysical methods including multi-angle light scattering and small-angle X-ray scattering. The structural core of SYCE1 is formed by amino acids 25-179, within the N-terminal half of the protein, which mediates SYCE1 dimerization. This alpha-helical core adopts a curved coiled-coil structure of 20-nm length in which the two chains are arranged in an anti-parallel configuration. This structure is retained within full-length SYCE1, in which long C-termini adopt extended conformations to achieve an elongated molecule of over 50 nm in length. The SYCE1 structure is compatible with it functioning as a physical strut that tethers other components to achieve structural stability of the SC central element.