scholarly journals ATP binding promotes light-induced structural changes to the protein moiety of Arabidopsis cryptochrome 1

2020 ◽  
Vol 19 (10) ◽  
pp. 1326-1331
Author(s):  
Tatsuya Iwata ◽  
Daichi Yamada ◽  
Katsuhiro Mikuni ◽  
Kazuya Agata ◽  
Kenichi Hitomi ◽  
...  
Keyword(s):  
Structural Changes ◽  
Proton Donor ◽  
Atp Binding ◽  
Cryptochrome 1 ◽  
Protein Moiety

D396 is protonated and acts as a proton donor to FAD in Arabidopsis cryptochome 1 only when ATP is bound.

Structural chemistry involved in information detection and transmission by gas sensor heme proteins: Resonance Raman investigation

2008 ◽  
Vol 80 (12) ◽  
pp. 2667-2678 ◽  
Author(s):  
Samir F. El-Mashtoly ◽  
Teizo Kitagawa
Keyword(s):  
Gas Sensor ◽  
Structural Changes ◽  
Catalytic Domain ◽  
Signal Transmission ◽  
Resonance Raman ◽  
Protein Activity ◽  
Sensor Proteins ◽  
Vinyl Group ◽  
Protein Moiety

A variety of heme-containing gas sensor proteins have been discovered by gene analysis from bacteria to mammals. In general, these proteins are composed of an N-terminal heme-containing sensor domain and a C-terminal catalytic domain. Binding of O2, CO, or NO to the heme causes a change in the structure of heme, which alters the protein conformation in the vicinity of the heme, and the conformational change is propagated to the catalytic domain, leading to regulation of the protein activity. This mini-review summarizes the recent resonance Raman studies obtained with both visible and UV excitation sources for two O2 sensor proteins, EcDOS and HemAT-Bs. These investigations have shown the role of heme propionate hydrogen-bonding interactions in communicating the heme structural changes, which occur upon ligand binding, from heme to the protein moiety. Furthermore, it is deduced that the contact interactions between the heme 2-vinyl group and the surrounding residues are also important for signal transmission from heme to protein in EcDOS.

Changes in the intrinsic electrocatalytic nature of Na+/K+ ATPase reflect structural changes on ATP-binding: Electrochemical label-free approach

2013 ◽  
Vol 27 ◽  
pp. 104-107 ◽  
Author(s):  
Jan Vacek ◽  
Martina Zatloukalova ◽  
Marika Havlikova ◽  
Jitka Ulrichova ◽  
Martin Kubala
Keyword(s):  
Structural Changes ◽  
Atp Binding ◽  
Label Free ◽  
Electrochemical Label

Novel ATP-binding and autophosphorylation activity associated with Arabidopsis and human cryptochrome-1

2003 ◽  
Vol 270 (14) ◽  
pp. 2921-2928 ◽  
Author(s):  
Jean-Pierre Bouly ◽  
Baldissera Giovani ◽  
Armin Djamei ◽  
Markus Mueller ◽  
Anke Zeugner ◽  
...  
Keyword(s):  
Atp Binding ◽  
Cryptochrome 1

scholarly journals Mitotic phosphorylation regulates Hsp72 spindle localization by uncoupling ATP binding from substrate release

2018 ◽  
Vol 11 (543) ◽  
pp. eaao2464 ◽  
Author(s):  
Manjeet Mukherjee ◽  
Sarah Sabir ◽  
Laura O’Regan ◽  
Josephina Sampson ◽  
Mark W. Richards ◽  
...  
Keyword(s):  
Mitotic Spindle ◽  
Structural Changes ◽  
Adenosine Diphosphate ◽  
Nucleotide Binding ◽  
Binding Domain ◽  
Atp Binding ◽  
Hsp70 Family ◽  
Chromosome Congression ◽  
Mitotic Phosphorylation ◽  
Substrate Binding Domain

Hsp72 is a member of the 70-kDa heat shock family of molecular chaperones (Hsp70s) that comprise a nucleotide-binding domain (NBD) and a substrate-binding domain (SBD) connected by a linker that couples the exchange of adenosine diphosphate (ADP) for adenosine triphosphate (ATP) with the release of the protein substrate. Mitotic phosphorylation of Hsp72 by the kinase NEK6 at Thr66 located in the NBD promotes the localization of Hsp72 to the mitotic spindle and is required for efficient spindle assembly and chromosome congression and segregation. We determined the crystal structure of the Hsp72 NBD containing a genetically encoded phosphoserine at position 66. This revealed structural changes that stabilized interactions between subdomains within the NBD. ATP binding to the NBD of unmodified Hsp72 resulted in the release of substrate from the SBD, but phosphorylated Hsp72 retained substrate in the presence of ATP. Mutations that prevented phosphorylation-dependent subdomain interactions restored the connection between ATP binding and substrate release. Thus, phosphorylation of Thr66 is a reversible mechanism that decouples the allosteric connection between nucleotide binding and substrate release, providing further insight into the regulation of the Hsp70 family. We propose that phosphorylation of Hsp72 on Thr66 by NEK6 during mitosis promotes its localization to the spindle by stabilizing its interactions with components of the mitotic spindle.

scholarly journals Time-resolved serial femtosecond crystallography reveals early structural changes in channelrhodopsin

eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Kazumasa Oda ◽  
Takashi Nomura ◽  
Takanori Nakane ◽  
Keitaro Yamashita ◽  
Keiichi Inoue ◽  
...  
Keyword(s):  
Conformational Changes ◽  
Structural Changes ◽  
Local Deformation ◽  
Proton Donor ◽  
Time Resolved ◽  
Molecular Events ◽  
Channel Opening ◽  
Ion Conducting ◽  
And Shifts ◽  
Opening And Closing

Channelrhodopsins (ChRs) are microbial light-gated ion channels utilized in optogenetics to control neural activity with light . Light absorption causes retinal chromophore isomerization and subsequent protein conformational changes visualized as optically distinguished intermediates, coupled with channel opening and closing. However, the detailed molecular events underlying channel gating remain unknown. We performed time-resolved serial femtosecond crystallographic analyses of ChR by using an X-ray free electron laser, which revealed conformational changes following photoactivation. The isomerized retinal adopts a twisted conformation and shifts toward the putative internal proton donor residues, consequently inducing an outward shift of TM3, as well as a local deformation in TM7. These early conformational changes in the pore-forming helices should be the triggers that lead to opening of the ion conducting pore.

scholarly journals Dynamics and Structural Changes Induced by ATP Binding in SAV1866, a Bacterial ABC Exporter

2010 ◽  
Vol 114 (48) ◽  
pp. 15948-15957 ◽  
Author(s):  
Jean-Paul Becker ◽  
Françoise Van Bambeke ◽  
Paul M. Tulkens ◽  
Martine Prévost
Keyword(s):  
Structural Changes ◽  
Atp Binding

scholarly journals Computational Modeling of NLRP3 Identifies Enhanced ATP Binding and Multimerization in Cryopyrin-Associated Periodic Syndromes

2020 ◽  
Vol 11 ◽  
Author(s):  
Jenny Mae Samson ◽  
Dinoop Ravindran Menon ◽  
Prasanna K. Vaddi ◽  
Nazanin Kalani Williams ◽  
Joanne Domenico ◽  
...  
Keyword(s):  
Computational Modeling ◽  
Protein Interactions ◽  
Nlrp3 Inflammasome ◽  
Structural Changes ◽  
Binding Pocket ◽  
Clinical Severity ◽  
Atp Binding ◽  
Inflammasome Activation ◽  
Bioinformatics Tools ◽  
Wells Syndrome

Cyropyrin-associated periodic syndromes (CAPS) are clinically distinct syndromes that encompass a phenotypic spectrum yet are caused by alterations in the same gene, NLRP3. Many CAPS cases and other NLRP3-autoinflammatory diseases (NLRP3-AIDs) are directly attributed to protein-coding alterations in NLRP3 and the subsequent dysregulation of the NLRP3 inflammasome leading to IL-1β-mediated inflammatory states. Here, we used bioinformatics tools, computational modeling, and computational assessments to explore the proteomic consequences of NLRP3 mutations, which potentially drive NLRP3 inflammasome dysregulation. We analyzed 177 mutations derived from familial cold autoinflammatory syndrome (FCAS), Muckle-Wells Syndrome (MWS), and the non-hereditary chronic infantile neurologic cutaneous and articular syndrome, also known as neonatal-onset multisystem inflammatory disease (CINCA/NOMID), as well as other NLRP3-AIDs. We found an inverse relationship between clinical severity and the severity of predicted structure changes resulting from mutations in NLRP3. Bioinformatics tools and computational modeling revealed that NLRP3 mutations that are predicted to be structurally severely-disruptive localize around the ATP binding pocket and that specific proteo-structural changes to the ATP binding pocket lead to enhanced ATP binding affinity by altering hydrogen-bond and charge interactions. Furthermore, we demonstrated that NLRP3 mutations that are predicted to be structurally mildly- or moderately-disruptive affect protein-protein interactions, such as NLRP3-ASC binding and NLRP3-NLRP3 multimerization, enhancing inflammasome formation and complex stability. Taken together, we provide evidence that proteo-structural mechanisms can explain multiple mechanisms of inflammasome activation in NLRP3-AID.

scholarly journals CX3CL1 binding protein-2 (CBP2) of Plasmodium falciparum binds nucleic acids

2019 ◽  
Author(s):  
Ritu Saxena ◽  
Jasweer Kaur ◽  
Rachna Hora ◽  
Palwinder Singh ◽  
Vineeta Singh ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Nucleic Acids ◽  
Host Cell ◽  
Immune Modulation ◽  
Structural Changes ◽  
Parasite Development ◽  
Atp Binding ◽  
Reducing Conditions ◽  
Parasite Biology

AbstractSeveral exported Plasmodium falciparum(Pf) proteins contribute to malaria biology through their involvement in cytoadherence, immune evasion and host cell remodelling. Many of these exported proteins and other host molecules are present in iRBC (infected red blood cell) generated extracellular vesicles (EVs), which are responsible for host cell modification and parasite development. CX3CL1 binding proteins (CBPs) present on the surface of iRBC have been reported to contribute to cytoadhesion by binding with the chemokine ‘CX3CL1’ via their extracellular domains. Here, we have characterized the cytoplasmic domain of CBP2to understand its function in parasite biology using biochemical and biophysical methods. Recombinant cytoplasmic CBP2 (rcCBP2) binds nucleic acids showing interaction with DNA/RNA. rcCBP2 shows dimer formation under non-reducing conditions highlighting the role of disulphide bonds in oligomerization while ATP binding leads to structural changes in the protein. In vitro interaction studies depict its binding with a Maurer’s cleft resident protein ‘PfSBP1’, which is influenced by ATP binding of rcCBP2. Our results suggest CBP2 as a two-transmembrane (2TM) receptor responsible for targeting EVs and delivering cargo to host endothelial cells. We propose CBP2 as an important molecule having roles in cytoadherence and immune modulation through its extracellular and cytoplasmic domains respectively.

Fine Structural Changes in the Microvasculature of the Mouse Pinna: Aging and Radiation Injury

1974 ◽  
Vol 32 ◽  
pp. 54-55
Author(s):  
S. Phyllis Steamer ◽  
Rosemarie L. Devine
Keyword(s):  
Structural Changes ◽  
Radiation Treatment ◽  
Arterial Stenosis ◽  
Ultrastructural Changes ◽  
Vascular Effects ◽  
Microvascular Changes ◽  
Surrounding Connective Tissue ◽  
Fission Neutrons ◽  
Total Body

The importance of radiation damage to the skin and its vasculature was recognized by the early radiologists. In more recent studies, vascular effects were shown to involve the endothelium as well as the surrounding connective tissue. Microvascular changes in the mouse pinna were studied in vivo and recorded photographically over a period of 12-18 months. Radiation treatment at 110 days of age was total body exposure to either 240 rad fission neutrons or 855 rad 60Co gamma rays. After in vivo observations in control and irradiated mice, animals were sacrificed for examination of changes in vascular fine structure. Vessels were selected from regions of specific interest that had been identified on photomicrographs. Prominent ultrastructural changes can be attributed to aging as well as to radiation treatment. Of principal concern were determinations of ultrastructural changes associated with venous dilatations, segmental arterial stenosis and tortuosities of both veins and arteries, effects that had been identified on the basis of light microscopic observations. Tortuosities and irregularly dilated vein segments were related to both aging and radiation changes but arterial stenosis was observed only in irradiated animals.

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