Model peptides mimic the structure and function of the N-terminus of the pore-forming toxin sticholysin II

Biopolymers ◽  
2006 ◽  
Vol 84 (2) ◽  
pp. 169-180 ◽  
Author(s):  
Fábio Casallanovo ◽  
Felipe J. F. de Oliveira ◽  
Fernando C. de Souza ◽  
Uris Ros ◽  
Yohanka Martínez ◽  
...  
Keyword(s):  
Structure And Function ◽  
N Terminus ◽  
And Function ◽  
Model Peptides

scholarly journals Structure-function analysis of Arabidopsis TOPLESS reveals fundamental conservation of repression mechanisms across eukaryotes

2020 ◽  
Author(s):  
Alexander R. Leydon ◽  
Wei Wang ◽  
Hardik P. Gala ◽  
Sabrina Gilmour ◽  
Samuel Juarez-Solis ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Function Analysis ◽  
Structure And Function ◽  
Environmental Cues ◽  
Auxin Response ◽  
Middle Domain ◽  
N Terminus ◽  
And Function ◽  
The Relationship ◽  
Repression Domain

SummaryThe plant corepressor TOPLESS (TPL) is recruited to a large number of loci that are selectively induced in response to developmental or environmental cues, yet the mechanisms by which it inhibits expression in the absence of these stimuli is poorly understood. Previously, we had used the N-terminus of Arabidopsis thaliana TPL to enable repression of a synthetic auxin response circuit in Saccharomyces cerevisiae (yeast). Here, we leveraged the yeast system to interrogate the relationship between TPL structure and function, specifically scanning for repression domains. We identified a potent repression domain in Helix 8 located within the CRA domain, which directly interacted with the Mediator middle domain subunits Med21 and Med10. Interactions between TPL and Mediator were required to fully repress transcription in both yeast and plants. In contrast, we found that multimer formation, a conserved feature of many corepressors, had minimal influence on the repression strength of TPL.

scholarly journals Characterizing the Structure and Function of the N-Terminus of Schizosaccharomyces Pombe Cdc5, a Pre-Mrna Splicing Factor

2014 ◽  
Vol 106 (2) ◽  
pp. 429a
Author(s):  
Scott E. Collier ◽  
Dungeng Peng ◽  
Markus Voehler ◽  
Nicholas Reiter ◽  
Melanie Ohi
Keyword(s):  
Schizosaccharomyces Pombe ◽  
Structure And Function ◽  
Mrna Splicing ◽  
Splicing Factor ◽  
N Terminus ◽  
And Function

scholarly journals N-linked Oligosaccharides Affect the Enzymatic Activity of CD39: Diverse Interactions between Seven N-linked Glycosylation Sites

2005 ◽  
Vol 16 (4) ◽  
pp. 1661-1672 ◽  
Author(s):  
James J. Wu ◽  
Lisa E. Choi ◽  
Guido Guidotti
Keyword(s):  
Enzymatic Activity ◽  
Surface Expression ◽  
Structure And Function ◽  
Surface Appearance ◽  
C Terminus ◽  
Glycosylation Sites ◽  
N Terminus ◽  
Membrane Bound ◽  
And Function ◽  
Diverse Interactions

Rat CD39, a membrane-bound ectonucleoside triphosphate diphosphohydrolase that hydrolyzes extracellular nucleoside tri- and diphosphates, has seven potential N-glycosylation sites at asparagine residues 73, 226, 291, 333, 375, 429, and 458. To determine their roles in the structure and function of CD39, we mutated these sites individually or in combination by replacing asparagine with serine or glutamine and analyzed the surface expression and the enzymatic activity of the mutants. The results indicate that rat CD39 can be glycosylated at all seven sites when expressed in COS7 cells. Glycosylation sites 73 at the N terminus, 333 in the middle, and 429 and 458 at the C terminus were principally required for cell surface appearance of enzymatically active CD39. Whereas deletion of these sites individually had modest effects on surface ATPase activity, some double deletions of these sites had major effects on both surface activity and expression. The importance of these N-glycosylation sites is recognizable in other members of the ectonucleoside triphosphate diphosphohydrolase family.

scholarly journals Repression by the Arabidopsis TOPLESS corepressor requires association with the core Mediator complex

eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Alexander R Leydon ◽  
Wei Wang ◽  
Hardik P Gala ◽  
Sabrina Gilmour ◽  
Samuel Juarez-Solis ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Structure And Function ◽  
Mediator Complex ◽  
Environmental Cues ◽  
Auxin Response ◽  
The Core ◽  
N Terminus ◽  
And Function ◽  
The Relationship ◽  
Repression Domain

The plant corepressor TOPLESS (TPL) is recruited to a large number of loci that are selectively induced in response to developmental or environmental cues, yet the mechanisms by which it inhibits expression in the absence of these stimuli is poorly understood. Previously, we had used the N-terminus of Arabidopsis thaliana TPL to enable repression of a synthetic auxin response circuit in Saccharomyces cerevisiae (yeast). Here, we leveraged the yeast system to interrogate the relationship between TPL structure and function, specifically scanning for repression domains. We identified a potent repression domain in Helix 8 located within the CRA domain, which directly interacted with the Mediator middle module subunits Med21 and Med10. Interactions between TPL and Mediator were required to fully repress transcription in both yeast and plants. In contrast, we found that multimer formation, a conserved feature of many corepressors, had minimal influence on the repression strength of TPL.

scholarly journals Structure and Function of the Saccharomyces cerevisiae Sir3 BAH Domain

2006 ◽  
Vol 26 (8) ◽  
pp. 3256-3265 ◽  
Author(s):  
Jessica J. Connelly ◽  
Peihua Yuan ◽  
Hao-Chi Hsu ◽  
Zhizhong Li ◽  
Rui-Ming Xu ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Protein A ◽  
Transcriptional Silencing ◽  
Structure And Function ◽  
Full Length ◽  
Left Handed ◽  
N Terminus ◽  
Bah Domain ◽  
And Function

ABSTRACT Previous work has shown that the N terminus of the Saccharomyces cerevisiae Sir3 protein is crucial for the function of Sir3 in transcriptional silencing. Here, we show that overexpression of N-terminal fragments of Sir3 in strains lacking the full-length protein can lead to some silencing of HML and HMR. Sir3 contains a BAH (bromo-adjacent homology) domain at its N terminus. Overexpression of this domain alone can lead to silencing as long as Sir1 is overexpressed and Sir2 and Sir4 are present. Overexpression of the closely related Orc1 BAH domain can also silence in the absence of any Sir3 protein. A previously characterized hypermorphic sir3 mutation, D205N, greatly improves silencing by the Sir3 BAH domain and allows it to bind to DNA and oligonucleosomes in vitro. A previously uncharacterized region in the Sir1 N terminus is required for silencing by both the Sir3 and Orc1 BAH domains. The structure of the Sir3 BAH domain has been determined. In the crystal, the molecule multimerizes in the form of a left-handed superhelix. This superhelix may be relevant to the function of the BAH domain of Sir3 in silencing.

scholarly journals Two structurally distinct domains of the nucleoporin Nup170 cooperate to tether a subset of nucleoporins to nuclear pores

2009 ◽  
Vol 185 (3) ◽  
pp. 387-395 ◽  
Author(s):  
Dirk Flemming ◽  
Phillip Sarges ◽  
Philipp Stelter ◽  
Andrea Hellwig ◽  
Bettina Böttcher ◽  
...  
Keyword(s):  
Pore Structure ◽  
Structure And Function ◽  
Nuclear Pore ◽  
Nuclear Pores ◽  
Terminal Domain ◽  
C Terminus ◽  
N Terminus ◽  
The Individual ◽  
And Function

How individual nucleoporins (Nups) perform their role in nuclear pore structure and function is largely unknown. In this study, we examined the structure of purified Nup170 to obtain clues about its function. We show that Nup170 adopts a crescent moon shape with two structurally distinct and separable domains, a β-propeller N terminus and an α-solenoid C terminus. To address the individual roles of each domain, we expressed these domains separately in yeast. Notably, overexpression of the Nup170 C domain was toxic in nup170Δ cells and caused accumulation of several Nups in cytoplasmic foci. Further experiments indicated that the C-terminal domain anchors Nup170 to nuclear pores, whereas the N-terminal domain functions to recruit or retain a subset of Nups, including Nup159, Nup188, and Pom34, at nuclear pores. We conclude that Nup170 performs its role as a structural adapter between cytoplasmically oriented Nups and the nuclear pore membrane.

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