scholarly journals Structural characterization of tau in fuzzy tau:tubulin complexes

2019 ◽  
Author(s):  
Ho Yee Joyce Fung ◽  
Kristen McKibben ◽  
Jennifer Ramirez ◽  
Kushol Gupta ◽  
Elizabeth Rhoades
Keyword(s):  
Structural Characterization ◽  
Neurodegenerative Disorders ◽  
Intrinsic Disorder ◽  
Structural Features ◽  
Dynamic Nature ◽  
Site Specific ◽  
Significant Interest ◽  
Environmentally Sensitive ◽  
A Site

SummaryTau is a neuronal microtubule (MT) associated protein of significant interest due to its association with several neurodegenerative disorders. Tau’s intrinsic disorder and the dynamic nature of its interactions with tubulin and MTs make its structural characterization challenging. Here we use an environmentally sensitive fluorophore as a site-specific probe of tau bound to soluble tubulin. Comparison of our results with recently published tau:MT cryo-EM model reveals structural similarities between tubulin- and MT-bound tau. Analysis of residues across the repeat regions reveal a hierarchy in tubulin occupancy, which may be relevant to tau’s ability to differentiate between tubulin and MTs. As binding to soluble tubulin is a critical first step in MT polymerization, our characterization of the structural features of tau in dynamic, fuzzy tau:tubulin assemblies advances our understanding of how tau functions in the cell and how function may be disrupted in disease.

scholarly journals Site-Specific Insertion of IS492 in Pseudoalteromonas atlantica

2009 ◽  
Vol 191 (20) ◽  
pp. 6408-6414 ◽  
Author(s):  
Brian P. Higgins ◽  
Adam C. Popkowski ◽  
Peter R. Caruana ◽  
Anna C. Karls
Keyword(s):  
Extracellular Polysaccharide ◽  
Structural Features ◽  
Target Site ◽  
Recombination Mechanism ◽  
Site Specific ◽  
Precise Excision ◽  
Pseudoalteromonas Atlantica ◽  
A Site ◽  
Site Recognition

ABSTRACT Reversible insertion of IS492 at a site within epsG on the Pseudoalteromonas atlantica chromosome controls peripheral extracellular polysaccharide production and biofilm formation by P. atlantica. High-frequency precise excision of IS492 from epsG requires 5 and 7 bp of flanking DNA, suggesting that IS492 transposition involves a site-specific recombination mechanism. The site specificity of IS492 insertion was examined in P. atlantica and shown to be specific for a 7-bp target, 5′-CTTGTTA-3′. Characterization of numerous insertion events at the target site in epsG indicated that insertion is also orientation specific. The frequency of IS492 insertion at the epsG target site (2.7 × 10−7/cell/generation), determined by quantitative PCR, is 4 to 5 orders of magnitude lower than the frequency of IS492 precise excision from the same site. Comparison of insertion sites for IS492 and the highly related ISPtu2 from Pseudoalteromonas tunicata suggests DNA sequence and/or structural features that may contribute to site recognition and recombination by the transposase of IS492.

scholarly journals Purification and Characterization of the R64 Shufflon-Specific Recombinase

2000 ◽  
Vol 182 (10) ◽  
pp. 2787-2792 ◽  
Author(s):  
Atsuko Gyohda ◽  
Teruya Komano
Keyword(s):  
Electrophoretic Analysis ◽  
Recombination Reaction ◽  
Site Specific ◽  
Dna Inversion ◽  
Repeat Sequences ◽  
In Vitro Recombination ◽  
Recombinase Gene ◽  
A Site

ABSTRACT The shufflon, a multiple DNA inversion system in plasmid R64, consists of four invertible DNA segments which are separated and flanked by seven 19-bp repeat sequences. The product of a site-specific recombinase gene, rci, promotes site-specific recombination between any two of the inverted 19-bp repeat sequences of the shufflon. To analyze the molecular mechanism of this recombination reaction, Rci protein was overproduced and purified. The purified Rci protein promoted the in vitro recombination reaction between the inverted 19-bp repeats of supercoiled DNA of a plasmid carrying segment A of the R64 shufflon. The recombination reaction was enhanced by the bacterial host factor HU. Gel electrophoretic analysis indicated that the Rci protein specifically binds to the DNA segments carrying the 19-bp sequences. The binding affinity of the Rci protein to the four shufflon segments as well as four synthetic 19-bp sequences differed greatly: among the four 19-bp repeat sequences, the repeat-a and -d sequences displayed higher affinity to Rci protein. These results suggest that the differences in the affinity of Rci protein for the 19-bp repeat sequences determine the inversion frequencies of the four segments.

scholarly journals Structural characterization of fibrous synthetic hydrogels using fluorescence microscopy

Soft Matter ◽  
2020 ◽  
Vol 16 (17) ◽  
pp. 4210-4219 ◽  
Author(s):  
Johannes Vandaele ◽  
Boris Louis ◽  
Kaizheng Liu ◽  
Rafael Camacho ◽  
Paul H. J. Kouwer ◽  
...  
Keyword(s):  
Fluorescence Microscopy ◽  
Structural Characterization ◽  
Crucial Role ◽  
Structural Features ◽  
The Matrix ◽  
Synthetic Hydrogels

The structural features of the matrix surrounding the cells play a crucial role in regulating their behavior.

Characterization of deoxyribozymes with site-specific oxidative cleavage activity against DNA obtained by in vitro selection

2016 ◽  
Vol 14 (7) ◽  
pp. 2347-2351 ◽  
Author(s):  
Ming-Qi Wang ◽  
Juan Dong ◽  
Huafan Zhang ◽  
Zhuo Tang
Keyword(s):  
In Vitro Selection ◽  
Oxidative Cleavage ◽  
Site Specific ◽  
New Class ◽  
Cleavage Activity ◽  
A Site

We have generated a new class of deoxyribozymes that required Mn2+ and Cu2+ to catalyze a site-specific oxidative cleavage of DNA.

Preparation and characterization of a viral DNA molecule containing a site-specific 2-aminofluorene adduct: A new probe for mutagenesis by carcinogens

Biochemistry ◽  
1986 ◽  
Vol 25 (2) ◽  
pp. 449-456 ◽  
Author(s):  
Dana L. Johnson ◽  
Thomas M. Reid ◽  
Mei-Sie Lee ◽  
Charles M. King ◽  
Louis J. Romano
Keyword(s):  
Viral Dna ◽  
Site Specific ◽  
Dna Molecule ◽  
A Site

scholarly journals Structural features and near infra-red (NIR) luminescence of isomeric Yb(iii) bipyridyl-N,N′-dioxide coordination polymers

2015 ◽  
Vol 44 (29) ◽  
pp. 13378-13383 ◽  
Author(s):  
Gail M. Sequeira ◽  
Wayne Y. Tan ◽  
Evan G. Moore
Keyword(s):  
Coordination Polymers ◽  
Structural Characterization ◽  
Lanthanide Complexes ◽  
Structural Features ◽  
X Ray ◽  
X Ray Crystallography ◽  
Infra Red ◽  
Nir Luminescence

The synthesis and structural characterization of a series of lanthanide complexes formed from YbX3 salts (X = NO3− or CF3SO3−) and the isomeric 4,4′-bipyridine-N,N′-dioxide (4,4′-bpdo) or 3,3′-bipyridine-N,N′-dioxide (3,3′-bpdo) ligands has been undertaken by X-ray crystallography.

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