Bioinformatic discovery of novel collagen-binding aggregation factors in lactic acid bacteria

Abstract

Lactic acid bacteria (LABs) are a unique group of microorganisms found in the diet of nearly all humans and form an integral part of the healthy human microbiome. Some LAB strains exhibit a remarkable ability for autoaggregation, mediated by Snowflake Forming Collagen Binding Aggregation Factors (SFCBAFs)—a fascinating group of proteins described so far only in LABs. To date, only five SFCBAFs have been characterized in detail: AggL from Lactococcus lactis, AggE from Enterococcus faecium, AggLb from Lacticaseibacillus paracasei, AggLr from Lactococcus raffinolactis, and AggA from Tetragenococcus halophilus. In this study, we present bioinformatically predicted novel SFCBAF candidates and demonstrate their widespread distribution among LAB species. Furthermore, we provide evidence that such proteins may not be exclusive to LABs, as homologous sequences were also identified in phylogenetically distant bacteria such as Staphylococcus aureus, Oceanobacillus spp., Bacillus spp., and others, expanding our understanding of this unique protein family