Large-Scale Analyses of Human Microbiomes Reveal Thousands of Small, Novel Genes.
Sberro H, Fremin BJ, Zlitni S, Edfors F, Greenfield N, Snyder MP, Pavlopoulos GA, Kyrpides NC, Bhatt AS
Cell. Aug 2019
COMMENT: This work is oriented to the detection and study of small proteins in human Microbiomes.
The authors carried out a comparative genomics analysis on 1,773 human-associated metagenomes from four different body sites:
The study was done analyzing healthy human microbiomes, represented by the NIH Human Microbiome Project (HMP) dataset (Lloyd-Priceet al., 2017).
The detection of small proteins was based on the idea that the sequence of the ORFs of small proteins should be conserved. The result of the analysis of the 1,773 metagenomes was the selection of 4,539 candidate small protein families, many of them not previously described.
Between the possible functions of these putative small proteins selected from metagenomes the authors highlighted these funtions:
• Antiphage activities
• Cell-cell communication
• Adaptation (proteins acquired by horizontal transfer)
• Antimicrobial activities
The authors provide evidence of transcription and translation for a subset of these families.
More metatranscriptomics and metaproteomics studies will be needed to select the actual small proteins from the set of candidate proteins. In any case this study has the focus in a many times forgotten type of proteins, the small proteins, that could have potential unexplored possibilities of application in human health.