The solute carrier (SLC) superfamily is the largest group of proteins responsible for the transmembrane transport of substances in human cells. It includes more than 400 members that are organized into 65 families according to their physiological function and sequence similarity. Different families of SLCs can adopt the same or different folds that determine the mechanism and reflect the evolutionary relationship between SLC members. Analysis of structural data in the literature before this work showed 13 different folds in the SLC superfamily covering 40 families and 343 members. To further study their mechanism, we systematically explored the SLC superfamily to look for more folds. Based on our results, at least three new folds are found for the SLC superfamily, one of which is in the choline-like transporter family (SLC44) and has been experimentally verified. Our work has laid a foundation and provided important insights for the systematic and comprehensive study of the structure and function of SLC.

溶质载体 (SLC) 超家族是负责人体细胞中物质跨膜转运的最大蛋白质组。它包括400多个成员，根据其生理功能和序列相似性分为65个家族。不同的 SLC 家族可以采用相同或不同的折叠来确定机制并反映 SLC 成员之间的进化关系。在这项工作之前对文献中的结构数据分析表明，SLC 超家族中有 13 个不同的折叠，涵盖 40 个家族和 343 个成员。为了进一步研究它们的机制，我们系统地探索了 SLC 超家族以寻找更多的折叠。根据我们的结果，SLC 超家族至少发现了三个新的折叠，其中之一属于胆碱样转运蛋白家族（SLC44），并已通过实验验证。我们的工作为系统、全面地研究SLC的结构和功能奠定了基础并提供了重要的启示。