scholarly journals Regulatory Control of Rishirilide(s) Biosynthesis in Streptomyces bottropensis

2021 ◽  
Vol 9 (2) ◽  
pp. 374
Author(s):  
Olga Tsypik ◽  
Roman Makitrynskyy ◽  
Xiaohui Yan ◽  
Hans-Georg Koch ◽  
Thomas Paululat ◽  
...  
Keyword(s):  
Biosynthetic Pathway ◽  
Specific Interaction ◽  
Biologically Active ◽  
Regulatory Proteins ◽  
Regulatory Control ◽  
Transcriptional Analysis ◽  
Positive Regulators ◽  
Dna Binding Affinity ◽  
Complex Regulation ◽  
Biochemical Analyses

Streptomycetes are well-known producers of numerous bioactive secondary metabolites widely used in medicine, agriculture, and veterinary. Usually, their genomes encode 20–30 clusters for the biosynthesis of natural products. Generally, the onset and production of these compounds are tightly coordinated at multiple regulatory levels, including cluster-situated transcriptional factors. Rishirilides are biologically active type II polyketides produced by Streptomyces bottropensis. The complex regulation of rishirilides biosynthesis includes the interplay of four regulatory proteins encoded by the rsl-gene cluster: three SARP family regulators (RslR1-R3) and one MarR-type transcriptional factor (RslR4). In this work, employing gene deletion and overexpression experiments we revealed RslR1-R3 to be positive regulators of the biosynthetic pathway. Additionally, transcriptional analysis indicated that rslR2 is regulated by RslR1 and RslR3. Furthermore, RslR3 directly activates the transcription of rslR2, which stems from binding of RslR3 to the rslR2 promoter. Genetic and biochemical analyses demonstrated that RslR4 represses the transcription of the MFS transporter rslT4 and of its own gene. Moreover, DNA-binding affinity of RslR4 is strictly controlled by specific interaction with rishirilides and some of their biosynthetic precursors. Altogether, our findings revealed the intricate regulatory network of teamworking cluster-situated regulators governing the biosynthesis of rishirilides and strain self-immunity.

The LARGE2-APO1/APO2 regulatory module controls panicle size and grain number in rice

2021 ◽  
Author(s):  
Luojiang Huang ◽  
Kai Hua ◽  
Ran Xu ◽  
Dali Zeng ◽  
Ruci Wang ◽  
...  
Keyword(s):  
Agronomic Traits ◽  
Loss Of Function ◽  
Grain Number ◽  
Hect Domain ◽  
Regulatory Module ◽  
Promising Target ◽  
Meristematic Activity ◽  
Positive Regulators ◽  
Genetic Mechanisms ◽  
Biochemical Analyses

Abstract Panicle size and grain number are important agronomic traits and influence grain yield in rice (Oryza sativa), but the molecular and genetic mechanisms underlying panicle size and grain number control remain largely unknown in crops. Here we report that LARGE2 encodes a HECT-domain E3 ubiquitin ligase OsUPL2 and regulates panicle size and grain number in rice. The loss of function large2 mutants produce large panicles with increased grain number, wide grains and leaves, and thick culms. LARGE2 regulates panicle size and grain number by repressing meristematic activity. LARGE2 is highly expressed in young panicles and grains. Biochemical analyses show that LARGE2 physically associates with ABERRANT PANICLE ORGANIZATION1 (APO1) and APO2, two positive regulators of panicle size and grain number, and modulates their stabilities. Genetic analyses support that LARGE2 functions with APO1 and APO2 in a common pathway to regulate panicle size and grain number. These findings reveal a novel genetic and molecular mechanism of the LARGE2-APO1/APO2 module-mediated control of panicle size and grain number in rice, suggesting that this module is a promising target for improving panicle size and grain number in crops.

scholarly journals Abrogation of Neuraminidase Reduces Biofilm Formation, Capsule Biosynthesis, and Virulence of Porphyromonas gingivalis

2011 ◽  
Vol 80 (1) ◽  
pp. 3-13 ◽  
Author(s):  
Chen Li ◽  
Kurniyati ◽  
Bo Hu ◽  
Jiang Bian ◽  
Jianlan Sun ◽  
...  
Keyword(s):  
Porphyromonas Gingivalis ◽  
Biofilm Formation ◽  
Adult Population ◽  
Transcriptional Analysis ◽  
Wild Type ◽  
Content Type ◽  
Multiple Organs ◽  
Biochemical Analyses

ABSTRACTThe oral bacteriumPorphyromonas gingivalisis a key etiological agent of human periodontitis, a prevalent chronic disease that affects up to 80% of the adult population worldwide.P. gingivalisexhibits neuraminidase activity. However, the enzyme responsible for this activity, its biochemical features, and its role in the physiology and virulence ofP. gingivalisremain elusive. In this report, we found thatP. gingivalisencodes a neuraminidase, PG0352 (SiaPg). Transcriptional analysis showed thatPG0352is monocistronic and is regulated by a sigma70-like promoter. Biochemical analyses demonstrated that SiaPgis an exo-α-neuraminidase that cleaves glycosidic-linked sialic acids. Cryoelectron microscopy and tomography analyses revealed that thePG0352deletion mutant (ΔPG352) failed to produce an intact capsule layer. Compared to the wild type,in vitrostudies showed that ΔPG352 formed less biofilm and was less resistant to killing by the host complement.In vivostudies showed that while the wild type caused a spreading type of infection that affected multiple organs and all infected mice were killed, ΔPG352 only caused localized infection and all animals survived. Taken together, these results demonstrate that SiaPgis an important virulence factor that contributes to the biofilm formation, capsule biosynthesis, and pathogenicity ofP. gingivalis, and it can potentially serve as a new target for developing therapeutic agents againstP. gingivalisinfection.

scholarly journals GuUGT, a glycosyltransferase from Glycyrrhiza uralensis , exhibits glycyrrhetinic acid 3- and 30-O-glycosylation

2019 ◽  
Vol 6 (10) ◽  
pp. 191121 ◽  
Author(s):  
Ying Huang ◽  
Da Li ◽  
Jinhe Wang ◽  
Yi Cai ◽  
Zhubo Dai ◽  
...  
Keyword(s):  
Biosynthetic Pathway ◽  
Glycyrrhetinic Acid ◽  
Glycyrrhiza Uralensis ◽  
Transcriptome Data ◽  
Bioactive Components ◽  
Triterpenoid Saponins ◽  
Genes Encoding ◽  
Engineered Yeast ◽  
Biochemical Analyses

Glycyrrhiza uralensis is a well-known herbal medicine that contains triterpenoid saponins as the predominant bioactive components, and these compounds include glycyrrhetinic acid (GA)-glycoside derivatives. Although two genes encoding UDP-glycosyltransferases (UGTs) that glycosylate these derivates have been functionally characterized in G. uralensis , the mechanisms of glycosylation by other UGTs remain unknown. Based on the available transcriptome data, we isolated a UGT with expression in the roots of G. uralensis . This UGT gene possibly encodes a glucosyltransferase that glycosylates GA derivatives at the 3-OH site. Biochemical analyses revealed that the recombinant UGT enzyme could transfer a glucosyl moiety to the free 3-OH or 30-COOH groups of GA. Furthermore, engineered yeast harbouring genes involved in the biosynthetic pathway for GA-glycoside derivates produced GA-3- O -β-D-glucoside, implying that the enzyme has GA 3-O-glucosyltransferase activity in vivo . Our results could provide a frame for understand the function of the UGT gene family, and also is important for further studies of triterpenoids biosynthesis in G. uralensis .

Structural insights into the interaction of p97 N-terminus domain and VBM in rhomboid protease, RHBDL4

2016 ◽  
Vol 473 (18) ◽  
pp. 2863-2880 ◽  
Author(s):  
Jia Jia Lim ◽  
Youngjin Lee ◽  
Tue Tu Ly ◽  
Jung Youn Kang ◽  
Jung-Gyu Lee ◽  
...  
Keyword(s):  
Complex Structure ◽  
Specific Interaction ◽  
Adaptor Proteins ◽  
Binding Mode ◽  
Binding Motif ◽  
Rhomboid Protease ◽  
Cofactor Binding ◽  
Arginine Residues ◽  
Biochemical Analyses ◽  
Structural Insights

RHBDL4 is an active rhomboid that specifically recognizes and cleaves atypical, positively charged transmembrane endoplasmic reticulum-associated degradation (ERAD) substrates. Interaction of valosin-containing protein (p97/VCP) and RHBDL4 is crucial to retrotranslocate polyubiquitinated substrates for ERAD pathway. Here, we report the first complex structure of VCP-binding motif (VBM) with p97 N-terminal domain (p97N) at 1.88 Å resolution. Consistent with p97 adaptor proteins including p47-ubiquitin regulatory X (UBX), gp78-VCP-interacting motif (VIM), OTU1-UBX-like element, and FAF1-UBX, RHBDL4 VBM also binds at the interface between the two lobes of p97N. Notably, the RF residues in VBM are involved in the interaction with p97N, showing a similar interaction pattern with that of FPR signature motif in the UBX domain, although the directionality is opposite. Comparison of VBM interaction with VIM of gp78, another α-helical motif that interacts with p97N, revealed that the helix direction is inversed. Nevertheless, the conserved arginine residues in both motifs participate in the majority of the interface via extensive hydrogen bonds and ionic interactions with p97N. We identified novel VBM-binding mode to p97N that involves a combination of two types of p97–cofactor specificities observed in the UBX and VIM interactions. This highlights the induced fit model of p97N interdomain cleft upon cofactor binding to form stable p97–cofactor complexes. Our mutational and biochemical analyses in defining the specific interaction between VBM and p97N have elucidated the importance of the highly conserved VBM, applicable to other VBM-containing proteins. We also showed that RHBDL4, ubiquitins, and p97 co-operate for efficient substrate dislocation.

Biologically active halo-substituted ferrocenyl thioureas: synthesis, spectroscopic characterization, and DFT calculations

2018 ◽  
Vol 42 (9) ◽  
pp. 7154-7165 ◽  
Author(s):  
Faiza Asghar ◽  
Sadaf Rana ◽  
Saira Fatima ◽  
Amin Badshah ◽  
Bhajan Lal ◽  
...  
Keyword(s):  
Dna Binding ◽  
Dft Calculations ◽  
Binding Affinity ◽  
Spectroscopic Characterization ◽  
Biologically Active ◽  
Dna Binding Affinity ◽  
Dna Binders

The DNA binding affinity of ferrocenyl complexes explored by CV and UV ascertain them as noble DNA binders. The computational measurements correlate well with the outcomes of electrochemistry and bio-activities.

scholarly journals Structural Genomics of Chromatin Regulators for Biological Discovery & Epigenetic Therapy

2014 ◽  
Vol 70 (a1) ◽  
pp. C33-C33
Author(s):  
Cheryl Arrowsmith
Keyword(s):  
Posttranslational Modifications ◽  
Regulatory Proteins ◽  
Epigenetic Therapy ◽  
Histone Tail ◽  
Nuclear Signaling ◽  
Chromatin Regulators ◽  
Family Approach ◽  
Biological Discovery ◽  
Key Features ◽  
Biochemical Analyses

We are taking a protein family approach to understand how human protein domains, enzymes and complexes recognize specific histone tail sequences and their posttranslational modifications. These are key mechanisms of nuclear signaling that regulate epigenetic cellular states and gene expression programs. Systematic structural and biochemical analyses are revealing key features of selectivity and regulation among these factors, enabling structure-based development of potent, selective, cell-active small molecule inhibitors of individual epigenetic regulatory proteins.

scholarly journals Genetic Manipulation of the Fusarium fujikuroi Fusarin Gene Cluster Yields Insight into the Complex Regulation and Fusarin Biosynthetic Pathway

2013 ◽  
Vol 20 (8) ◽  
pp. 1055-1066 ◽  
Author(s):  
Eva-Maria Niehaus ◽  
Karin Kleigrewe ◽  
Philipp Wiemann ◽  
Lena Studt ◽  
Christian M.K. Sieber ◽  
...  
Keyword(s):  
Gene Cluster ◽  
Biosynthetic Pathway ◽  
Genetic Manipulation ◽  
Fusarium Fujikuroi ◽  
Complex Regulation ◽  
Insight Into

scholarly journals Alginate synthesis by Pseudomonas aeruginosa: a key pathogenic factor in chronic pulmonary infections of cystic fibrosis patients.

1991 ◽  
Vol 4 (2) ◽  
pp. 191-206 ◽  
Author(s):  
T B May ◽  
D Shinabarger ◽  
R Maharaj ◽  
J Kato ◽  
L Chu ◽  
...  
Keyword(s):  
Cystic Fibrosis ◽  
Pseudomonas Aeruginosa ◽  
Biosynthetic Pathway ◽  
Pulmonary Infection ◽  
Regulatory Mechanism ◽  
Regulatory Proteins ◽  
Host Immune System ◽  
Pathogenic Factor ◽  
Pulmonary Infections

Pulmonary infection by mucoid, alginate-producing Pseudomonas aeruginosa is the leading cause of mortality among patients suffering from cystic fibrosis. Alginate-producing P. aeruginosa is uniquely associated with the environment of the cystic fibrosis-affected lung, where alginate is believed to increase resistance to both the host immune system and antibiotic therapy. Recent evidence indicates that P. aeruginosa is most resistant to antibiotics when the infecting cells are present as a biofilm, as they appear to be in the lungs of cystic fibrosis patients. Inhibition of the protective alginate barrier with nontoxic compounds targeted against alginate biosynthetic and regulatory proteins may prove useful in eradicating P. aeruginosa from this environment. Our research has dealt with elucidating the biosynthetic pathway and regulatory mechanism(s) responsible for alginate synthesis by P. aeruginosa. This review summarizes reports on the role of alginate in cystic fibrosis-associated pulmonary infections caused by P. aeruginosa and provides details about the biosynthesis and regulation of this exopolysaccharide.

Activation of ras p21 transforming properties associated with an increase in the release rate of bound guanine nucleotide

1986 ◽  
Vol 6 (12) ◽  
pp. 4214-4220
Author(s):  
J C Lacal ◽  
S A Aaronson
Keyword(s):  
Slow Rate ◽  
Active Form ◽  
Biologically Active ◽  
Regulatory Proteins ◽  
Guanine Nucleotide ◽  
Nucleotide Exchange ◽  
Activating Mutations ◽  
Temperature Requirements ◽  
Nucleotide Release ◽  
Ras P21

An Ala-to-Thr substitution at position 59 activates the transforming properties of the p21ras protein without impairment of GTPase activity, a biochemical alteration associated with other activating mutations. To investigate the basis for the transforming properties of the Thr-59 mutant, we characterized guanine nucleotide release. This reaction exhibited a slow rate and stringent temperature requirements. To further dissect the release reaction, we used monoclonal antibodies directed against different epitopes of the p21 molecule. One monoclonal specifically interfered with nucleotide release, while others which recognized different regions of the molecule blocked nucleotide binding. Mutants with the Thr-59 substitution exhibited a three- to ninefold-higher rate of GDP and GTP release than normal p21 or mutants with other activating lesions. This alteration in the Thr-59 mutant would have the effect of increasing its rate of nucleotide exchange. In an intracellular environment with a high GTP/GDP ratio, this would favor the association of GTP with the Thr-59 mutant. Consistent with knowledge of known G-regulatory proteins, these findings support a model in which the p21-GTP complex is the biologically active form of the p21 protein.

scholarly journals Deletion of a regulatory gene within the cpk gene cluster reveals novel antibacterial activity in Streptomyces coelicolor A3(2)

Microbiology ◽  
2010 ◽  
Vol 156 (8) ◽  
pp. 2343-2353 ◽  
Author(s):  
Marco Gottelt ◽  
Stefan Kol ◽  
Juan Pablo Gomez-Escribano ◽  
Mervyn Bibb ◽  
Eriko Takano
Keyword(s):  
Antibacterial Activity ◽  
Gene Cluster ◽  
Polyketide Synthase ◽  
Streptomyces Coelicolor ◽  
Regulatory Gene ◽  
Feedback Mechanism ◽  
Biologically Active ◽  
Transcriptional Analysis ◽  
Type I ◽  
Negative Feedback Mechanism

Genome sequencing of Streptomyces coelicolor A3(2) revealed an uncharacterized type I polyketide synthase gene cluster (cpk). Here we describe the discovery of a novel antibacterial activity (abCPK) and a yellow-pigmented secondary metabolite (yCPK) after deleting a presumed pathway-specific regulatory gene (scbR2) that encodes a member of the γ-butyrolactone receptor family of proteins and which lies in the cpk gene cluster. Overproduction of yCPK and abCPK in a scbR2 deletion mutant, and the absence of the newly described compounds from cpk deletion mutants, suggest that they are products of the previously orphan cpk biosynthetic pathway in which abCPK is converted into the yellow pigment. Transcriptional analysis suggests that scbR2 may act in a negative feedback mechanism to eventually limit yCPK biosynthesis. The results described here represent a novel approach for the discovery of new, biologically active compounds.

Sign in / Sign up

Export Citation Format

Share Document