The S-adenosylmethionine carrier (SAMC) is a membrane transport protein located on the inner membrane of mitochondria that catalyzes the import of S-adenosylmethionine (SAM) into the mitochondrial matrix. SAMC mutations can cause a series of mitochondrial defects, including those affecting RNA stability, protein modification, mitochondrial translation and biosynthesis. Here, we describe the expression, purification and oligomerization of SAMC. The SAMC genes from three species were cloned into a eukaryotic expression vector with a GFP tag, and confocal microscopy analysis showed that these SAMCs were localized to mitochondria. A BacMam expression system was used for the expression of D. rerio SAMC with a FLAG tag. A size-exclusion chromatography analysis showed that SAMC may form a hexamer. A negative-staining electron microscopy analysis showed that SAMC formed tiny uniform particles and also confirmed the oligomerization of SAMC.

中文翻译：

---

S-腺苷甲硫氨酸转运蛋白的表达，纯化和低聚。

S-腺苷甲硫氨酸载体（SAMC）是一种位于线粒体内膜上的膜转运蛋白，可催化S-腺苷甲硫氨酸（SAM）进入线粒体基质。SAMC突变可引起一系列线粒体缺陷，包括那些影响RNA稳定性，蛋白质修饰，线粒体翻译和生物合成的缺陷。在这里，我们描述了SAMC的表达，纯化和寡聚。将来自三个物种的SAMC基因克隆到带有GFP标签的真核表达载体中，共聚焦显微镜分析表明这些SAMC位于线粒体中。BacMam表达系统用于表达带有FLAG标签的D. rerio SAMC。尺寸排阻色谱分析表明SAMC可形成六聚体。