scholarly journals Nucleotide binding triggers a conformational change of the CBS module of the magnesium transporter CNNM2 from a twisted towards a flat structure

2014 ◽  
Vol 464 (1) ◽  
pp. 23-34 ◽  
Author(s):  
María Ángeles Corral-Rodríguez ◽  
Marchel Stuiver ◽  
Guillermo Abascal-Palacios ◽  
Tammo Diercks ◽  
Iker Oyenarte ◽  
...  
Keyword(s):  
Conformational Change ◽  
Nucleotide Binding ◽  
Conformational Flexibility ◽  
Flat Structure ◽  
Magnesium Transporter

Nucleotide binding triggers a conformational change of the Bateman module of the magnesium transporter CNNM2. The hypomagnesaemia-causing mutation T568I impairs MgATP binding and limits the conformational flexibility of this protein module.

scholarly journals Activation mechanism of ATP-sensitive K+ channels explored with real-time nucleotide binding

eLife ◽  
2019 ◽  
Vol 8 ◽  
Author(s):  
Michael Puljung ◽  
Natascia Vedovato ◽  
Samuel Usher ◽  
Frances Ashcroft
Keyword(s):  
Conformational Change ◽  
Ionic Currents ◽  
Nucleotide Binding ◽  
Activation Mechanism ◽  
Time Resolved ◽  
K Channels ◽  
Novel Approach ◽  
Binding Event ◽  
Fluorescent Nucleotides

The response of ATP-sensitive K+ channels (KATP) to cellular metabolism is coordinated by three classes of nucleotide binding site (NBS). We used a novel approach involving labeling of intact channels in a native, membrane environment with a non-canonical fluorescent amino acid and measurement (using FRET with fluorescent nucleotides) of steady-state and time-resolved nucleotide binding to dissect the role of NBS2 of the accessory SUR1 subunit of KATP in channel gating. Binding to NBS2 was Mg2+-independent, but Mg2+ was required to trigger a conformational change in SUR1. Mutation of a lysine (K1384A) in NBS2 that coordinates bound nucleotides increased the EC50 for trinitrophenyl-ADP binding to NBS2, but only in the presence of Mg2+, indicating that this mutation disrupts the ligand-induced conformational change. Comparison of nucleotide-binding with ionic currents suggests a model in which each nucleotide binding event to NBS2 of SUR1 is independent and promotes KATP activation by the same amount.

Conformation of cross-linked aspartate transcarbamoylase

1981 ◽  
Vol 59 (5) ◽  
pp. 371-378 ◽  
Author(s):  
William W.-C. Chan
Keyword(s):  
Conformational Change ◽  
Conformational Flexibility ◽  
The Other ◽  
Native Enzyme ◽  
Aspartate Transcarbamoylase ◽  
Cross Linking ◽  
Aspartate Transcarbamylase ◽  
Substrate Analogues ◽  
T State ◽  
Substrate Concentrations

We have previously shown that aspartate transcarbamylase loses its substrate cooperativity after modification with a cross-linking reagent. Depending on the presence or absence of substrate analogues during cross-linking, the derivatives resemble the relaxed (R) or taut (T) state, respectively. In the present study, we attempt to characterize the conformation of these derivatives and the effects of ligands.The putative T-state derivative was similar to the native enzyme in its reactivity towards p-hydroxymercuribenzoate and in the increase of reactivity upon addition of succinate. However, unlike the native enzyme it was not activated by succinate at low substrate concentrations. On the other hand, the putative R-state derivative showed greatly enhanced reactivity which was not substantially increased by succinate. In the presence of urea, the native enzyme and the two cross-linked derivatives all resembled the R state. Thus at low substrate concentrations urea activated both the native enzyme and the T-state derivative. In contrast, the effect of urea on the R state derivative is mainly inhibitory.The above results show that the R state has been definitely stabilized whereas the T-state derivative retains some conformational flexibility. Our observations also indicate that the conformational change induced by succinate has two distinct components of which only one is allowed in the T-state derivative.

Nucleotide binding kinetics and conformational change analysis of tissue transglutaminase with switchSENSE

2020 ◽  
Vol 605 ◽  
pp. 113719 ◽  
Author(s):  
Regina Staffler ◽  
Ralf Pasternack ◽  
Martin Hils ◽  
Wolfgang Kaiser ◽  
Friederike M. Möller
Keyword(s):  
Conformational Change ◽  
Tissue Transglutaminase ◽  
Nucleotide Binding ◽  
Binding Kinetics ◽  
Change Analysis

Conformational flexibility in DNA structure and its implications in understanding the organization of DNA in chromatin

1978 ◽  
Vol 283 (997) ◽  
pp. 295-298 ◽  
Keyword(s):  
Nucleic Acid ◽  
Conformational Change ◽  
Dna Structure ◽  
Conformational Flexibility ◽  
Base Pairs ◽  
X Ray ◽  
Nucleosome Structure ◽  
Mixed Sugar ◽  
Sugar Puckering

X-ray crystallographic studies of drug-nucleic acid crystalline complexes have suggested that DNA first bends or ‘kinks’ before accepting an intercalative drug or dye. This flexibility in DNA structure is made possible by altering the normal C2' endo deoxyribose sugar puckering in B DNA to a mixed sugar puckering pattern of the type C3' endo (S'-S') C2' endo and partially unstacking base pairs. A kinking scheme such as this would require minimal stereochemical rearrangement and would also involve small energies. This has prompted us to ask more generally if a conformational change such as this could be used by proteins in their interactions with DNA. Here we describe an interesting superhelical DNA structure formed by kinking DNA every ten base pairs. This structure may be used in the organization of DNA within the nucleosome structure in chromatin.

Conformational Change of the Loop L5 in Rice Kinesin Motor Domain Induced by Nucleotide Binding

2006 ◽  
Vol 139 (5) ◽  
pp. 857-864 ◽  
Author(s):  
Nobuhisa Umeki ◽  
Toshiaki Mitsui ◽  
Kazunori Kondo ◽  
Shinsaku Maruta
Keyword(s):  
Conformational Change ◽  
Nucleotide Binding ◽  
Motor Domain ◽  
Kinesin Motor

scholarly journals Structures of monomeric and dimeric PRC2:EZH1 reveal flexible modules involved in chromatin compaction

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Daniel Grau ◽  
Yixiao Zhang ◽  
Chul-Hwan Lee ◽  
Marco Valencia-Sánchez ◽  
Jenny Zhang ◽  
...  
Keyword(s):  
Gene Silencing ◽  
Conformational Change ◽  
Conformational Flexibility ◽  
Catalytic Subunit ◽  
Biological Functions ◽  
Polycomb Repressive Complex ◽  
Chromatin Compaction ◽  
Polycomb Repressive Complex 2 ◽  
Selective Incorporation ◽  
Nucleosome Binding

AbstractPolycomb repressive complex 2 (PRC2) is a histone methyltransferase critical for maintaining gene silencing during eukaryotic development. In mammals, PRC2 activity is regulated in part by the selective incorporation of one of two paralogs of the catalytic subunit, EZH1 or EZH2. Each of these enzymes has specialized biological functions that may be partially explained by differences in the multivalent interactions they mediate with chromatin. Here, we present two cryo-EM structures of PRC2:EZH1, one as a monomer and a second one as a dimer bound to a nucleosome. When bound to nucleosome substrate, the PRC2:EZH1 dimer undergoes a dramatic conformational change. We demonstrate that mutation of a divergent EZH1/2 loop abrogates the nucleosome-binding and methyltransferase activities of PRC2:EZH1. Finally, we show that PRC2:EZH1 dimers are more effective than monomers at promoting chromatin compaction, and the divergent EZH1/2 loop is essential for this function, thereby tying together the methyltransferase, nucleosome-binding, and chromatin-compaction activities of PRC2:EZH1. We speculate that the conformational flexibility and the ability to dimerize enable PRC2 to act on the varied chromatin substrates it encounters in the cell.

Allosteric modulation of the sarcoplasmic reticulum Ca2+ ATPase by thapsigargin via decoupling of functional motions

2019 ◽  
Vol 21 (39) ◽  
pp. 21991-21995 ◽  
Author(s):  
Noureldin Saleh ◽  
Yong Wang ◽  
Poul Nissen ◽  
Kresten Lindorff-Larsen
Keyword(s):  
Sarcoplasmic Reticulum ◽  
Conformational Change ◽  
Nucleotide Binding ◽  
Allosteric Modulation ◽  
Cytoplasmic Domains ◽  
Transmembrane Regions

Thapsigargin binding to the Ca2+-ATPase SERCA induces a conformational change in the transmembrane regions without regulation of the cytoplasmic domains, and causes a conformational change in the cytoplasmic domains uncoupled from nucleotide binding.

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