Biology subjects

Pei, T.

Publications and source records attributed to Pei, T..

4 recordsLinked to original sources

bioRxiv2026

Functional activation reveals a repressor-gated fourth type VI secretion system in clinical Pseudomonas aeruginosa

Pseudomonas aeruginosa is a major opportunistic pathogen in which the type VI secretion system (T6SS) contributes to interbacterial competition and virulence. While most strains encode three T6SSs, we here functionally characterize a fourth system (H4-T6SS) in a clinical P. aeruginosa isolate. The H4-T6SS gene cluster is transcriptionally silent under laboratory conditions. By promoter rewiring, we demonstrate that the H4-T6SS assembles a contractile machine and mediates effector secretion and robust inter- and intraspecific antagonism. We identify a dominant pore-forming effector and its secretion pathway and a silent yet conserved nuclease effector. Genetic and biochemical analyses show that H4-T6SS expression is activated by an H4-encoded transcriptional regulator and repressed by H-NS family proteins. Analysis of over 1,200 clinical isolates reveals that the H4-T6SS is distributed across lineages and geographic regions. Finally, we observe functional crosstalk between H4- and H2-T6SSs. Together, these findings establish H4-T6SS as a functional and repressor-gated secretion system that expands the competitive arsenal of clinical P. aeruginosa.

microbiology↗

bioRxiv2025

AI-HEAD: Auto-indexing for Helical assembles' diffraction and fast dynamic structure determination

Analyzing the structure of the helical assembly is very important to excavate the mechanism of base life activities such as cell morphology maintaining, cargo transportation, et. al. However, the structure determination of helical assembles still challenging due to ambiguous of helical parameters. Here, we developed automatic, fast and accurate helical parameter and structure calculation method AI-HEAD, which perform diffraction indexing and parameter calculation automatically in seconds, and determine the final structure unambiguously by sorting parameters semi-automatically. AI-HEAD is open source and also provides a user-friendly graphical interface.

biophysics↗

bioRxiv2021

Characterization of glucosyltransferase and glucuronosyltransferase family members reveals how major flavone glycoside accumulate in the root of Scutellaria baicalensis

Flavonoid glycosides extracted from roots of Scutellaria baicalensis exhibit strong pharmaceutical effect in antitumor, antioxidative, anti-inflammatory, and antiviral activity. UDP glycosyltransferase family members are responsible for the transfer of a glycosyl moiety from UDP sugars to a wide range of acceptor flavonoids. Here, we report the phylogenetic analysis, tissue-specific expression and biochemical characterization of 10 glucosyltrasferases (SbUGTs) and 6 glucuronosyltransferases (SbUGATs) based on the recently released genome of S. baicalensis. These results reveal that the high expression level and affinity to substrate of SbUGAT4 make baicalin become the richest flavonoid glycoside in the root of S. baicalensis.

plant biology↗

bioRxiv2020

The genome analysis of Tripterygium wilfordii reveals TwCYP712K1 and TwCYP712K2 responsible for oxidation of friedelin in celastrol biosynthesis pathway

ABSTRACTTripterygium wilfordii is a Traditional Chinese Medicine (TCM) from family Celastraceae and celastrol is one of the strongest active ingredients belonging to friedelane-type pentacyclic triterpenoid, which has a large clinical application value of anti-tumor, immunosuppression, and obesity treatment. The first committed biosynthesis step of celastrol is the cyclization of 2, 3-oxidosqualene to friedelin, catalyzed by the oxidosqualene cyclase, while the rest of this pathway is still unclear. In this study, we reported a reference genome assembly of T. wilfordii with high-quality annotation by using a hybrid sequencing strategy (Nanopore, Bionano, Illumina HiSeq, and Pacbio), which obtained a 340.12 Mb total size and contig N50 reached 3.09 Mb. In addition, we successfully anchored 91.02% sequences into 23 pseudochromosomes using Hi-C technology and the super-scaffold N50 reached 13.03 Mb. Based on integration genome, transcriptom and metabolite analyses, as well as in vivo and in vitro enzyme assays, two CYP450 genes, TwCYP712K1 and TwCYP712K2 have been proven for C-29 position oxidation of friedelin to produce polpunonic acid, which clarifies the second biosynthesis step of celastrol. Syntenic analysis revealed that TwCYP712K1 and TwCYP712K2 derived from the common ancestor. These results have provided insight into illustrating pathways for both celastrol and other bioactive compounds found in this plant.Competing Interest StatementThe authors have declared no competing interest.View Full Text

plant biology↗