Splicing factor proline- and glutamine-rich (SFPQ) is an RNA-binding protein, playing significant roles in gene regulation and subnuclear body formation. Our recent serendipitous discovery showed that SFPQ binds zinc directly and forms an infinite polymer that is induced by zinc binding to the protein. The zinc-induced reversible polymerization has led us to exploit this property to develop a rapid purification strategy for SFPQ without the use of affinity tags. In combination with the variation of ionic strength for salting-out of SFPQ, the reversible zinc-induced precipitation of SFPQ reduced the purification time required to obtain pure SFPQ to a single day. The purified protein was subjected to the previously reported crystallization condition. The resulting crystals diffracted to 2.22 Å resolution, confirming the quality of SFPQ purified with this new rapid purification strategy.

剪接因子富含脯氨酸和谷氨酰胺（SFPQ）是一种RNA结合蛋白，在基因调节和亚核小体形成中发挥重要作用。我们最近的偶然发现表明，SFPQ直接与锌结合并形成无限的聚合物，该聚合物由锌与蛋白质的结合诱导。锌诱导的可逆聚合使我们能够利用这一特性来开发不使用亲和标签的SFPQ快速纯化策略。结合用于SFPQ盐析的离子强度变化，可逆的锌诱导的SFPQ沉淀将获得纯SFPQ所需的纯化时间减少到一天。使纯化的蛋白质经受先前报道的结晶条件。所得晶体衍射至2.22Å分辨率，