Small proteins encoded by small open-reading frames (sORFs) (≤70 aa) were overlooked for decades due to methodological reasons and are thus often missing in genome annotations. Novel detection methods such as ribosome profiling (Ribo-Seq) and mass spectrometry optimized for small proteins (peptidomics) have opened up a new field of interest and several catalogs of small proteins in bacteria and archaea have been recently reported. Many translated sORFs have been discovered in genomic locations previously thought to be noncoding, such as 5′ or 3′ untranslated regions or well-studied regulatory small RNAs (sRNAs). Even within longer ORFs, additional functional sORFs have been detected. Today, only a small proportion is characterized, but those small proteins indicate important and diverse functions in cellular physiology. Here, we summarize recently characterized small proteins involved in microbial metabolism.

由于方法学原因，由小开放阅读框（sORF）（≤70 个氨基酸）编码的小蛋白质几十年来一直被忽视，因此在基因组注释中经常缺失。核糖体分析 (Ribo-Seq) 和针对小蛋白质优化的质谱分析（肽组学）等新型检测方法开辟了一个新的研究领域，最近报道了细菌和古细菌中小蛋白质的多个目录。在以前被认为是非编码的基因组位置中发现了许多翻译的 sORF，例如 5' 或 3' 非翻译区或经过充分研究的调节性小 RNA (sRNA)。即使在较长的 ORF 中，也检测到了额外的功能性 sORF。如今，只有一小部分蛋白质被表征，但这些小蛋白质表明了细胞生理学中重要且多样化的功能。在这里，我们总结了最近表征的参与微生物代谢的小蛋白质。