ИСТИНА

Aspergillus fungi are ubiquitous and inhabit various ecological niches. Some of them are saprophytic, some may facultatively cause plant or animal infections, and extracellular hydrolytic enzymes play a key role in adaptations to these diverse lifestyles. Among those, extracellular peptidases have the widest range of substrates to cleave. We decided to describe repertoires of extracellular peptidases for Aspergillus fungi. This may shed light on the evolution of fungal proteolytic systems, reveal relationships between lifestyle and set of produced peptidases and their inhibitors and uncover dependencies between phylogeny of Aspergillus and these enzymes. 98 sequenced and assembled Aspergillus genomes were downloaded from Mycocosm and GenBank, some of them were manually annotated using AUGUSTUS. To predict peptidases and their inhibitors, a python-based tool previously created in our group, called Protty and available on GitHub was used. Extracellular enzymes were left after SignalP preprocessing and manual validation of the results. It was found that there are representatives of 14 peptidase families, namely A01, G01, M14, M19, M20, M28, M35, M36, M43, S01, S08, S10, S28, S53. Among them there are endo- , olygo- and exopeptidases, and the majority of the peptidases encoded in the genome are exopeptidases, which suggests that they probably mainly serve for nutrition. However, some rare and unique examples were also found, and their detailed functions going beyond nutrition are to be discovered. Interestingly, black Aspergilli have the highest (up to 10) number of aspergillopepsins (family A01 and G01). Interestingly, the number of encoded inhibitors varied from 0 to 7 for different species. However, their precise mechanism of action and role in physiology needs to be studied in more detail. Thus, the set of fungal extracellular peptidases reflects fungal lifestyle and its features may be taken into account when studying fungal ecology. Such complex bioinformatic investigations may help in identification of peptidases with high potential for biomedicine and biotechnology when working with genomes of novel species.