Structural comparison of yeast and human intra-mitochondrial lipid transport systems

2016 ◽  
Vol 44 (2) ◽  
pp. 479-485 ◽  
Author(s):  
Xeni Miliara ◽  
Stephen Matthews

Mitochondria depend on a tightly regulated supply of phospholipids. The protein of relevant evolutionary and lymphoid interest (PRELI)/Ups1 family together with its mitochondrial chaperones [TP53-regulated inhibitor of apoptosis 1 (TRIAP1)/Mdm35] represents a unique heterodimeric lipid-transfer system that is evolutionary conserved from yeast to man. Recent X-ray crystal structures of the human and yeast systems are compared and discuss here and shed new insight into the mechanism of the PRELI/Ups1 system.

2004 ◽  
Vol 60 (4) ◽  
pp. 481-489 ◽  
Author(s):  
Valeria Ferretti ◽  
Paola Gilli ◽  
Pier Andrea Borea

β-Carbolines are a class of drug which can interact with a high affinity with the benzodiazepine (BDZ) binding site of the GABAA receptor. The present paper, aimed at obtaining a deeper insight into the structure–properties relationships of this class of molecules, reports the crystal structures of four β-carbolines: ZK93423 (3-carboethoxy-4-methoxymethyl-6-benzyloxy-β-carboline), ZK91296 (3-carboethoxy-4-methoxymethyl-5-benzyloxy-β-carboline), FG7142 (N-methyl-3-carbamoyl-β-carboline) and the low-affinity ligand harmine hydrochloride (1-methyl-7-methoxy-β-carboline). This set of structural data is completed by the X-ray structures of other carbolines of known biological activity retrieved from the Cambridge Crystallographic Database and by the structures of β-CCE (3-carboethoxy-β-carboline), 6-PBC (3-carboethoxy-4-methoxymethyl-6-isopropoxy-β-carboline), PRCC (3-isopropoxy-β-carboline) and ZK93426 (3-carboethoxy-4-methyl-5-isopropoxy-β-carboline), which have been obtained by molecular-mechanics simulations. The structural features of all these molecules have been compared according to the stereochemical model we proposed in 1987. The structural comparison is integrated by the Free–Wilson analysis on 32 β-carbolines of known binding affinity data.


Author(s):  
Rubén Granero-García ◽  
Francesca P. A. Fabbiani

The structure of a 1:1 β-cyclodextrin–dimethylformamide hydrated complex has been determined from single-crystal X-ray diffraction data. A complete study of the structure is presented herein, including invariom refinement and interaction energy calculations. The structure has unit-cell parameters that are different from those of other β-cyclodextrin complexes crystallizing in the same space group, but exhibits the known herringbone packing type. A structural comparison of these complexes has been carried out withXPacin order to understand the origin of the differences in packing and unit-cell parameters. The results show that the differences are most likely ascribed to variations in hydration and in the hydrogen-bonded network.


2019 ◽  
Author(s):  
Xin Bian ◽  
Zhao Zhang ◽  
Pietro De Camilli ◽  
Chenxiang Lin

AbstractNon-vesicular lipid transport between bilayers at membrane contact sites plays important physiological roles. Mechanistic insight into the action of lipid transport proteins localized at these sites (bridge/tunnel versus shuttle models) requires a determination of the distance between bilayers at which this transport can occur. Here, we developed DNA-origami nanostructures to organize size-defined liposomes at precise distances and used them to study lipid transfer by the SMP domain of E-Syt1. Pairs of DNA ring-templated donor and acceptor liposomes were docked through DNA pillars, which determined their distance. The SMP domain was anchored to donor liposomes via an unstructured linker and lipid transfer was assessed via a FRET-based assay. We show that lipid transfer can occur over distances that exceed the length of SMP dimer, compatible with a shuttle model. The DNA nanostructures developed here can be adapted to study other processes occurring where two membranes are closely apposed to each other.


Author(s):  
J. M. Paque ◽  
R. Browning ◽  
P. L. King ◽  
P. Pianetta

Geological samples typically contain many minerals (phases) with multiple element compositions. A complete analytical description should give the number of phases present, the volume occupied by each phase in the bulk sample, the average and range of composition of each phase, and the bulk composition of the sample. A practical approach to providing such a complete description is from quantitative analysis of multi-elemental x-ray images.With the advances in recent years in the speed and storage capabilities of laboratory computers, large quantities of data can be efficiently manipulated. Commercial software and hardware presently available allow simultaneous collection of multiple x-ray images from a sample (up to 16 for the Kevex Delta system). Thus, high resolution x-ray images of the majority of the detectable elements in a sample can be collected. The use of statistical techniques, including principal component analysis (PCA), can provide insight into mineral phase composition and the distribution of minerals within a sample.


2019 ◽  
Author(s):  
Nobutaka Fujieda ◽  
Sachiko Yanagisawa ◽  
Minoru Kubo ◽  
Genji Kurisu ◽  
Shinobu Itoh

To unveil the activation of dioxygen on the copper centre (Cu<sub>2</sub>O<sub>2</sub>core) of tyrosinase, we performed X-ray crystallograpy with active-form tyrosinase at near atomic resolution. This study provided a novel insight into the catalytic mechanism of the tyrosinase, including the rearrangement of copper-oxygen species as well as the intramolecular migration of copper ion induced by substrate-binding.<br>


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Ye Qian ◽  
Yan Zhang ◽  
Haoming Ji ◽  
Yucheng Shen ◽  
Liangfeng Zheng ◽  
...  

Abstract Background Lung adenocarcinoma (LUAD) is one of the most common cancers with high morbidity and mortality worldwide. Long non-coding RNAs (lncRNAs) serve as tumor promoters or suppressors in the development of various human malignancies, including LUAD. Although long intergenic non-protein coding RNA 1089 (LINC01089) suppresses the progression of breast cancer, its mechanism in LUAD requires further exploration. Thus, we aimed to investigate the underlying function and mechanism of LINC01089 in LUAD. Methods The expression of LINC01089 in LUAD and normal cell lines was detected. Functional assays were applied to measure cell proliferation, apoptosis and migration. Besides, mechanism experiments were employed for assessing the interplay among LINC01089, miR-301b-3p and StAR related lipid transfer domain containing 13 (STARD13). Data achieved in this study was statistically analyzed with Student’s t test or one-way analysis of variance. Results LINC01089 expression was significantly down-regulated in LUAD tissues and cells and its overexpression could reduce cell proliferation and migration. Moreover, LINC01089 could regulate STARD13 expression through competitively binding to miR-301b-3p in LUAD. Additionally, rescue assays uncovered that STARD13 depletion or miR-301b-3p overexpression could countervail the restraining effect of LINC01089 knockdown on the phenotypes of LUAD cells. Conclusion LINC01089 served as a tumor-inhibitor in LUAD by targeting miR-301b-3p/STARD13 axis, providing an innovative insight into LUAD therapies. Trial registration Not applicable.


2000 ◽  
Vol 53 (8) ◽  
pp. 627 ◽  
Author(s):  
Piotr Storoniak ◽  
Karol Krzyminski ◽  
Pawel Dokurno ◽  
Antoni Konitz ◽  
Jerzy Blazejowski

The crystal structures of 10-methylacridinium chloride monohydrate, bromide monohydrate and iodide were determined by X-ray analysis. The compounds crystallize in the triclinic space group, P¯1, with 2 molecules in the unit cell. The molecular arrangement in the crystals revealed that hydrogen bonds (in hydrates) and van der Waals contacts play a significant part in intermolecular interactions. To discover their nature, contributions to the crystal lattice energy arising from electrostatic (the most important since the compounds form ionic crystals), dispersive and repulsive interactions were calculated. Enthalpies of formation of the salts, their stability and susceptibility to decomposition could be predicted from a combination of crystal lattice energies with values of other thermochemical characteristics obtained theoretically or taken from the literature. The role of water in the stabilization of the crystal lattice of the hydrates is also explained. The information gathered has given an insight into the features and behaviour of compounds which can be regarded as models of a large group of aromatic quaternary nitrogen salts.


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