Department of Medicine (Hematology; Blood and Marrow Transplantation) and Genetics, Stanford University, Stanford, CA, USA; Department of Genetics, Stanford University, Stanford, CA, USA.
Department of Medicine (Hematology; Blood and Marrow Transplantation) and Genetics, Stanford University, Stanford, CA, USA.
Cell. 2019 Aug 22;178(5):1245-1259.e14. doi: 10.1016/j.cell.2019.07.016. Epub 2019 Aug 8.
Small proteins are traditionally overlooked due to computational and experimental difficulties in detecting them. To systematically identify small proteins, we carried out a comparative genomics study on 1,773 human-associated metagenomes from four different body sites. We describe >4,000 conserved protein families, the majority of which are novel; ∼30% of these protein families are predicted to be secreted or transmembrane. Over 90% of the small protein families have no known domain and almost half are not represented in reference genomes. We identify putative housekeeping, mammalian-specific, defense-related, and protein families that are likely to be horizontally transferred. We provide evidence of transcription and translation for a subset of these families. Our study suggests that small proteins are highly abundant and those of the human microbiome, in particular, may perform diverse functions that have not been previously reported.
由于在检测小分子蛋白时存在计算和实验上的困难，传统上人们往往会忽视它们。为了系统地鉴定小分子蛋白，我们对来自四个不同身体部位的 1773 个人类相关宏基因组进行了比较基因组学研究。我们描述了>4000 个保守的蛋白质家族，其中大多数是新的；这些蛋白质家族中约有 30%被预测为分泌蛋白或跨膜蛋白。超过 90%的小分子蛋白家族没有已知的结构域，几乎一半的家族在参考基因组中没有代表。我们鉴定了一些可能具有保守功能、哺乳动物特有的、与防御相关的和可能发生水平转移的蛋白质家族。我们提供了这些家族中一部分具有转录和翻译活性的证据。我们的研究表明，小分子蛋白的丰度非常高，特别是人类微生物组中的小分子蛋白可能具有以前未报道过的多样化功能。
