scholarly journals Novel cryo-EM structure of an ADP-bound GroEL–GroES complex

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Sofia S. Kudryavtseva ◽  
Evgeny B. Pichkur ◽  
Igor A. Yaroshevich ◽  
Aleksandra A. Mamchur ◽  
Irina S. Panina ◽  
...  
Keyword(s):  
Relative Orientation ◽  
Dependent Manner ◽  
Bacterial Protein ◽  
Substrate Protein ◽  
System Functioning ◽  
Atp Binding And Hydrolysis ◽  
Cis And Trans ◽  
In Cis ◽  
Structural Methods ◽  
Groes Chaperonin

AbstractThe GroEL–GroES chaperonin complex is a bacterial protein folding system, functioning in an ATP-dependent manner. Upon ATP binding and hydrolysis, it undergoes multiple stages linked to substrate protein binding, folding and release. Structural methods helped to reveal several conformational states and provide more information about the chaperonin functional cycle. Here, using cryo-EM we resolved two nucleotide-bound structures of the bullet-shaped GroEL–GroES1 complex at 3.4 Å resolution. The main difference between them is the relative orientation of their apical domains. Both structures contain nucleotides in cis and trans GroEL rings; in contrast to previously reported bullet-shaped complexes where nucleotides were only present in the cis ring. Our results suggest that the bound nucleotides correspond to ADP, and that such a state appears at low ATP:ADP ratios.

scholarly journals Transgene Repeat Arrays Interact With Distant Heterochromatin and Cause Silencing in cis and trans

Genetics ◽  
1997 ◽  
Vol 147 (3) ◽  
pp. 1181-1190 ◽  
Author(s):  
Douglas R Dorer ◽  
Steven Henikoff
Keyword(s):  
Transgene Expression ◽  
Tandem Repeats ◽  
Position Effect ◽  
Position Effect Variegation ◽  
Dependent Manner ◽  
Repeat Array ◽  
Naturally Occurring ◽  
Homologous Position ◽  
Cis And Trans ◽  
In Cis

Tandem repeats of Drosophila transgenes can cause heterochromatic variegation for transgene expression in a copy-number and orientation-dependent manner. Here, we demonstrate different ways in which these transgene repeat arrays interact with other sequences at a distance, displaying properties identical to those of a naturally occurring block of interstitial heterochromatin. Arrays consisting of tandemly repeated white transgenes are strongly affected by proximity to constitutive heterochromatin. Moving an array closer to heterochromatin enhanced variegation, and enhancement was reverted by recombination of the array onto a normal sequence chromosome. Rearrangements that lack the array enhanced variegation of white on a homologue bearing the array. Therefore, silencing of white genes within a repeat array depends on its distance from heterochromatin of the same chromosome or of its paired homologue. In addition, white transgene arrays cause variegation of a nearby gene in cis, a hallmark of classical position-effect variegation. Such spreading of heterochromatic silencing correlates with array size. Finally, white transgene arrays cause pairing-dependent silencing of a non-variegating white insertion at the homologous position.

scholarly journals Hydrogen Peroxide Oxidation of Coordinated Thiocyanate Ion in cis- and trans-[Coen2NH3NCS]2+: The Preparation and Properties of trans-[Coen2NH3CN]2+

1973 ◽  
Vol 51 (24) ◽  
pp. 4152-4158 ◽  
Author(s):  
Albert Richard Norris ◽  
James William Lennox Wilson
Keyword(s):  
Hydrogen Peroxide ◽  
Spectral Properties ◽  
Peroxide Oxidation ◽  
Reaction Conditions ◽  
Thiocyanate Ion ◽  
Hydrogen Peroxide Oxidation ◽  
Percent Conversion ◽  
Cis And Trans ◽  
In Cis

The hydrogen peroxide oxidation of thiocyanate ion in cis- and trans-[Coen2NH3NCS]2+ leads to the formation of the corresponding cis- and trans-cyanoammine- and diamminebis(ethylenediamine)cobalt-(III) complexes. The spectral properties of the previously unreported trans-[Coe2NH3CN]2+ are reported and compared to the spectral properties of the cis-isomer.Observations are made concerning the reaction conditions which favor a high percent conversion of trans-[Coen2NH3NCS]2+ to trans-[Coen2NH3CN]2+.

Structure and chemical bonding in cis- and trans-M(NO)2(O2CR)2 (M=Cr and Mo) complexes

Polyhedron ◽  
2000 ◽  
Vol 19 (26-27) ◽  
pp. 2565-2572 ◽  
Author(s):  
Ludmiła Szterenberg ◽  
Szczepan Roszak ◽  
Renata Matusiak ◽  
Antoni Keller
Keyword(s):  
Chemical Bonding ◽  
Cis And Trans ◽  
In Cis

Hydrogen bonding and conformation in cis- and trans-2-alkoxy-3-hydroxytetrahydrofurans

1968 ◽  
Vol 46 (1) ◽  
pp. 21-24 ◽  
Author(s):  
W. W. Zajac Jr. ◽  
F. Sweet ◽  
R. K. Brown
Keyword(s):  
Hydrogen Bonding ◽  
Infrared Spectra ◽  
Hydroxyl Absorption ◽  
Cis And Trans ◽  
In Cis ◽  
Infrared Data ◽  
Hydrogen Bonded

Infrared spectra show both free and hydrogen bonded hydroxyl absorption in several trans-2-alkoxy-3-hydroxytetrahydrofurans. The extent of non-bonded hydroxyl is greater than that of bonded hydroxyl. Suggestions are made of possible conformations which might account for the infrared data.

Spectroscopic Study of Photosensitized Oxidation of Polyisoprene

1977 ◽  
Vol 50 (4) ◽  
pp. 704-713 ◽  
Author(s):  
M. A. Golub ◽  
M. L. Rosenberg ◽  
R. V. Gemmer
Keyword(s):  
Zero Order ◽  
Double Bonds ◽  
Photosensitized Oxidation ◽  
The Third ◽  
Type Process ◽  
Zero Order Kinetics ◽  
Hydroperoxide Formation ◽  
Cis And Trans ◽  
In Cis ◽  
Suitable Measure

Abstract The microstructural changes which occur in cis- and trans-1,4-polyisoprenes and in squalene during photosensitized oxidation were investigated with the aid of infrared and proton and carbon-13 NMR spectroscopy. The singlet oxygenation of these isoprenic compounds resulted in allylic hydroperoxides with shifted double bonds, according to the expected “ene”-type process. In contrast to trans-1,4-polyisoprene and squalene, which displayed the three possible double bond shifts, cis-1,4-polyisoprene showed essentially two of the shifts (to di- and trisubstituted double bonds) and very little of the third (to exomethylene groups). A suitable measure of the extent of hydroperoxidation was afforded by the absorbance ratio, A3400/A1440≡A′. Similar correlations of A′ with oxygen uptake were obtained for the three isoprenic compounds, using chlorophyll or methylene blue as sensitizer. The use of rose bengal gave erratic results indicative of some autoxidation accompanying the hydroperoxide formation. The singlet oxygenation followed zero-order kinetics, the relative rates for cis- and trans-1,4-polyisoprenes being approximately 1.0:1.5.

Pyrrolidine ring puckering in cis and trans-proline residues in proteins and polypeptides

1992 ◽  
Vol 228 (3) ◽  
pp. 725-734 ◽  
Author(s):  
E.James Milner-White ◽  
Lachlan H. Bell ◽  
Peter H. Maccallum
Keyword(s):  
Pyrrolidine Ring ◽  
Ring Puckering ◽  
Cis And Trans ◽  
In Cis
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