Putative methyltranferase LaeA and LaeA-like proteins, conserved in many filamentous fungi, regulate fungal growth, development, virulence, the biosynthesis of secondary metabolites, and the production of cellulolytic enzymes. Penicillium oxaliucm is a typical fungus that produces cellulolytic enzymes. In this study, we reported the biological function of eight putative methyltransferases (PoMtr23C/D/E/F/G/H and PoMtr25A/B) containing a methyltransf_23 or methyltransf_25 domain, with a focus on their roles in the production of cellulolytic enzymes. In P. oxalicum, various methyltransferase genes displayed different transcriptional levels. The genes Pomtr23C and Pomtr25A exhibited high transcriptional levels, while Pomtr23D/E/F/G/H and Pomtr25B were transcribed constantly at low levels. The gene deletion mutants (Δmtr23C/D/E/F/G/H and Δmtr25A/B) were constructed. Various mutants have different patterns in cellulolytic enzyme production. Compared to the WT, the largest increase in filter paper activity (FPA, indicating total cellulase activity) was observed in the Δmtr23G mutant, the only mutant with a cellulolytic halo surrounding the colony. Three mutants (Δmtr23C/D and Δmtr25A) also showed increased cellulolytic enzyme production. The Δmtr23E and Δmtr25B mutants displayed decreased FPA activity, while the Δmtr23F and Δmtr23H mutants displayed similar patterns of cellulolytic enzyme production compared with the WT. The assay of transcriptional levels of cellobiohydrolase gene Pocbh1 and β-1,4-endoglucanase Poeg1 supported that higher cellulolytic gene transcription resulted in higher production of cellulolytic enzymes, and vice versa. The transcriptional levels of two transcription factors, activator XlnR and repressor CreA, were measured. The high transcription level of the PoxlnR gene in the Δmtr23D mutant should be one reason for the increased transcription of its cellulolytic enzyme gene. Both XlnR and CreA transcriptional levels increased in the Δmtr23G mutant, but the former showed a more significant increase than the latter, indicating that the activation effect predominated. The PoMtr25A is localized in the nucleus. The catalytic subunit SNF2 of the SWI/SNF chromatin-remodeling complex was found as one of the interacting proteins of PoMtr25A via tandem affinity purification coupled with mass spectrometry. PoMtr25A may affect not only the transcription of repressor CreA but also by recruiting SWI/SNF complexes that affect chromatin structure, thereby regulating the transcription of target genes.

The Qinghai-Tibet Plateau, known as “the third pole” of the Earth, boasts unique climatic conditions with abundant sunlight, low temperature, and significant annual temperature variations, nurturing a diverse array of soil microorganisms with rich metabolic products. In this study, 132 fungal isolates were isolated and identified from the soil samples collected in Nyingchi, Tibet, belonging to 32 genera and 59 species, while Ascomycota, Mucoromycota, and Basidiomycota accounted for 91.7%, 7.5%, and 0.8%, respectively. The evolutionary relationships among 59 representative strains were revealed by constructing a phylogenetic tree, while Penicillium, Fusarium, and Aspergillus were the most widespread fungal genera here, and the antibacterial activity of these strains was evaluated by the agar diffusion assay, leading to 27 active strains. Notably, six of them demonstrated significant activities against two or more tested bacteria. The antibacterial efficacy of the extracts of these six fungi, which were derived from four distinct media, was further evaluated at a concentration of 500 μg/mL. This study provides a valuable supplement to the investigations of cultivable soil fungi in Nyingchi, Tibet, laying a foundation for the development of soil fungi and antibacterial lead compounds in the area.

Protein allostery, one of the crucial mechanisms in which proteins play and regulate their functions, is a biological process that affects active sites by perturbing allosteric sites. The recognition of allosteric sites holds vital importance in drug design and enzyme engineering. Consequently, detecting potential allosteric sites is increasingly drawing widespread attention in the realm of allosteric research. Several approaches have been proposed for predicting allosteric sites based on computer simulation techniques and traditional machine learning algorithms using pocket features. However, these methods either require extremely high computational resources and long sampling time or rely heavily on designed features. In this paper, we propose a novel method consisting of Protein Structure Bidirectional Encoder Representations from Transformers (PsBERT) and Protein Structure Masked Language Model (PsMLM) Pre-training Task to detect allosteric sites. Our model aims to enhance the encoder's comprehension of protein structures through the pre-training task, thus achieving the goal of predicting allosteric sites based on sequence information and coordinate information. Extensive experiments we conducted on the ASD2023 dataset demonstrate the effectiveness of our model.

Biological control fungi play an important role in the management of plant-parasitic nematodes; however, the molecular basis underlying their diverse biocontrol strategies remains incompletely understood. In this study, a comparative genomic analysis was performed on four representative biocontrol fungi, Purpureocillium lilacinum PLFJ-1, Trichoderma harzianum CBS 226.95, Pochonia chlamydosporia 170, and Aspergillus niger CBS 513.88. Genome comparison revealed substantial variation in genome size, GC content, and gene composition among the four fungi. Phylogenetic analysis divided these fungi into two major clades corresponding to distinct evolutionary lineages. Orthogroup analysis identified both a conserved core gene set and species-specific gene repertoires. Functional annotation based on KEGG, KOG, and GO indicated a high degree of conservation in core metabolic processes, catalytic activities, and cellular components, accompanied by distinct differences in specific functional categories. Further comparative analyses demonstrated pronounced variation in the composition and abundance of carbohydrate-active enzymes (CAZymes) and peptidases, as well as a notable expansion and enrichment of S8 subtilisin-like serine peptidases in the nematode-parasitic fungi P. lilacinum and P. chlamydosporia. Secondary metabolite analysis identified diverse biosynthetic gene clusters, with differences in PKS and NRPS distribution among species. Together, these findings suggest that distinct enzymatic and metabolic gene repertoires, particularly expansions of S8 serine peptidases and specific CAZyme families, may contribute to the biocontrol potential of these fungi.

Biological control fungi play an important role in the management of plant-parasitic nematodes; however, the molecular basis underlying their diverse biocontrol strategies remains incompletely understood. In this study, a comparative genomic analysis was performed on four representative biocontrol fungi: Purpureocillium lilacinum PLFJ-1, Trichoderma harzianum CBS 226.95, Pochonia chlamydosporia 170, and Aspergillus niger CBS 513.88. Genome comparison revealed substantial variation: genome size ranged from 34.0 Mb (A. niger) to 44.2 Mb (P. chlamydosporia), GC content from 47.5% (T. harzianum) to 58.5% (P. lilacinum), and predicted gene models also differed markedly among the four fungi. Phylogenetic analysis based on the Internal Transcribed Spacer divided these fungi into two major clades corresponding to distinct evolutionary lineages. Orthogroup analysis identified both a conserved core gene set and species-specific gene repertoires. Functional annotation using KEGG, KOG, and GO indicated a high degree of conservation across core metabolic processes, catalytic activities, and cellular components, with distinct differences within specific functional categories. Further comparative analyses demonstrated pronounced variation in the composition and abundance of carbohydrate-active enzymes (CAZymes) and peptidases, as well as a notable expansion and enrichment of S8 subtilisin-like serine peptidases in the nematode-parasitic fungi P. lilacinum and P. chlamydosporia. Secondary metabolite analysis revealed lineage-specific biosynthetic gene clusters (BGCs). Notably, P. lilacinum and P. chlamydosporia carried PKS/NRPS clusters potentially linked to nematicidal activity, while A. niger and T. harzianum displayed broader but less infection-specific metabolic profiles. Together, these findings suggest that distinct enzymatic and metabolic gene repertoires, particularly expansions of S8 serine peptidases and specific CAZyme families, may contribute to the biocontrol potential of these fungi.