scholarly journals High-Resolution Crystal Structure of RpoS Fragment Including a Partial Region 1.2 and Region 2 from the Intracellular Pathogen Legionella pneumophila

2017 ◽  
Author(s):  
Nannan Zhang ◽  
Xiaofang Chen ◽  
Xiaojian Gong ◽  
Tao Li ◽  
Zhiyuan Xie ◽  
...  
Keyword(s):  
Crystal Structure ◽  
High Resolution ◽  
Legionella Pneumophila ◽  
Transcription Initiation ◽  
Intracellular Pathogen ◽  
Regulatory Factor ◽  
Conserved Residues ◽  
Partial Region ◽  
Distinct Mechanism ◽  
Rnap Binding

Legionella pneumophila RpoS (LpRpoS) is an alternative sigma factor of RNA polymerase (RNAP) essential for virulence and stress resistance. To investigate the mechanism of RpoS in the intracellular pathogen L. pneumophila, we determined the high-resolution crystal structure of the LpRpoS (residues 95-194) containing a partial region 1.2 and region 2. The structure of LpRpoS (residues 95-194) reveals that the conserved residues are critical for promoter melting, DNA and core RNAP binding. The differences in regulatory factor binding site between Escherichia coli RpoS and LpRpoS suggest that LpRpoS may employ a distinct mechanism to recruit alternative regulatory factors controlling transcription initiation.

scholarly journals High-Resolution Crystal Structure of RpoS Fragment including a Partial Region 1.2 and Region 2 from the Intracellular Pathogen Legionella pneumophila

Crystals ◽  
2018 ◽  
Vol 8 (2) ◽  
pp. 54
Author(s):  
Nannan Zhang ◽  
Xiaofang Chen ◽  
Xiaojian Gong ◽  
Tao Li ◽  
Zhiyuan Xie ◽  
...  
Keyword(s):  
Crystal Structure ◽  
High Resolution ◽  
Legionella Pneumophila ◽  
Intracellular Pathogen ◽  
Partial Region

scholarly journals Molecular mechanism for the subversion of the retromer coat by theLegionellaeffector RidL

2017 ◽  
Vol 114 (52) ◽  
pp. E11151-E11160 ◽  
Author(s):  
Miguel Romano-Moreno ◽  
Adriana L. Rojas ◽  
Chad D. Williamson ◽  
David C. Gershlick ◽  
María Lucas ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Protein Interactions ◽  
Legionella Pneumophila ◽  
Molecular Mimicry ◽  
Microbial Pathogens ◽  
Intracellular Pathogen ◽  
Hairpin Loop ◽  
Domain Family ◽  
Ankyrin Repeat Protein ◽  
Endosomal Membranes

Microbial pathogens employ sophisticated virulence strategies to cause infections in humans. The intracellular pathogenLegionella pneumophilaencodes RidL to hijack the host scaffold protein VPS29, a component of retromer and retriever complexes critical for endosomal cargo recycling. Here, we determined the crystal structure ofL. pneumophilaRidL in complex with the human VPS29–VPS35 retromer subcomplex. A hairpin loop protruding from RidL inserts into a conserved pocket on VPS29 that is also used by cellular ligands, such as Tre-2/Bub2/Cdc16 domain family member 5 (TBC1D5) and VPS9-ankyrin repeat protein for VPS29 binding. Consistent with the idea of molecular mimicry in protein interactions, RidL outcompeted TBC1D5 for binding to VPS29. Furthermore, the interaction of RidL with retromer did not interfere with retromer dimerization but was essential for association of RidL with retromer-coated vacuolar and tubular endosomes. Our work thus provides structural and mechanistic evidence into how RidL is targeted to endosomal membranes.

High resolution STEM imaging study on high Tc superconductor YBa2CuaO7-x

1988 ◽  
Vol 46 ◽  
pp. 882-883
Author(s):  
H.-J. Ou ◽  
J. M. Cowley
Keyword(s):  
Crystal Structure ◽  
High Resolution ◽  
Grain Boundary ◽  
Strong Field ◽  
Imaging Study ◽  
Structure Defects ◽  
High Tc ◽  
High Tc Superconductor ◽  
Diffraction Patterns ◽  
Lattice Planes

Using the dedicate VG-HB5 STEM microscope, the crystal structure of high Tc superconductor of YBa2Cu3O7-x has been studied via high resolution STEM (HRSTEM) imaging and nanobeam (∽3A) diffraction patterns. Figure 1(a) and 2(a) illustrate the HRSTEM image taken at 10' times magnification along [001] direction and [100] direction, respectively. In figure 1(a), a grain boundary with strong field contrast is seen between two crystal regions A and B. The grain boundary appears to be parallel to a (110) plane, although it is not possible to determine [100] and [001] axes as it is in other regions which contain twin planes [3]. Following the horizontal lattice lines, from left to right across the grain boundary, a lattice bending of ∽4° is noticed. Three extra lattice planes, indicated by arrows, were found to terminate at the grain boundary and form dislocations. It is believed that due to different chemical composition, such structure defects occur during crystal growth. No bending is observed along the vertical lattice lines.

High resolution mapping of nucleic acid containing complexes in vitro and in situ

1996 ◽  
Vol 54 ◽  
pp. 48-49
Author(s):  
D. P. Bazett-Jones ◽  
M. J. Hendzel
Keyword(s):  
Nucleic Acid ◽  
High Resolution ◽  
Transcription Initiation ◽  
Molecular Mechanisms ◽  
Heavy Atom ◽  
Regulation Of Transcription ◽  
High Exposure ◽  
Resolution Mapping ◽  
Tata Sequence

Structural analysis of combinations of nucleosomes and transcription factors on promoter and enhancer elements is necessary in order to understand the molecular mechanisms responsible for the regulation of transcription initiation. Such complexes are often not amenable to study by high resolution crystallographic techniques. We have been applying electron spectroscopic imaging (ESI) to specific problems in molecular biology related to transcription regulation. There are several advantages that this technique offers in studies of nucleoprotein complexes. First, an intermediate level of spatial resolution can be achieved because heavy atom contrast agents are not necessary. Second, mass and stoichiometric relationships of protein and nucleic acid can be estimated by phosphorus detection, an element in much higher proportions in nucleic acid than protein. Third, wrapping or bending of the DNA by the protein constituents can be observed by phosphorus mapping of the complexes. Even when ESI is used with high exposure of electrons to the specimen, important macromolecular information may be provided. For example, an image of the TATA binding protein (TBP) bound to DNA is shown in the Figure (top panel). It can be seen that the protein distorts the DNA away from itself and much of its mass sits off the DNA helix axis. Moreover, phosphorus and mass estimates demonstrate whether one or two TBP molecules interact with this particular promoter TATA sequence.

Perovskite Solar Cells: Crystal Structure and Interface Architecture with High Resolution TEM Observations

2017 ◽  
Author(s):  
Satoshi Uchida ◽  
Tae Woong Kim ◽  
Ludmila Cojocaru ◽  
Takashi Kondo ◽  
Hiroshi Segawa
Keyword(s):  
Crystal Structure ◽  
Solar Cells ◽  
High Resolution ◽  
Perovskite Solar Cells ◽  
High Resolution Tem

scholarly journals Ipr1 Regulation by Cyclic GMP-AMP Synthase/Interferon Regulatory Factor 3 and Modulation of Irgm1 Expression via p53

2020 ◽  
Vol 40 (8) ◽  
Author(s):  
Fayang Liu ◽  
Hongni Xue ◽  
Jie Ke ◽  
Yongyan Wu ◽  
Kezhen Yao ◽  
...  
Keyword(s):  
Cyclic Gmp ◽  
Viral Infections ◽  
Pathogen Resistance ◽  
Interferon Regulatory Factor ◽  
Intracellular Pathogen ◽  
Regulatory Factor ◽  
Interferon Regulatory Factor 3 ◽  
Promoter Characterization ◽  
Ribosomal Protein L11 ◽  
Pathogenic Infection

ABSTRACT Intracellular pathogen resistance 1 (Ipr1) has been found to be a mediator to integrate cyclic GMP-AMP synthase (cGAS)–interferon regulatory factor 3 (IRF3), activated by intracellular pathogens, with the p53 pathway. Previous studies have shown the process of Ipr1 induction by various immune reactions, including intracellular bacterial and viral infections. The present study demonstrated that Ipr1 is regulated by the cGAS-IRF3 pathway during pathogenic infection. IRF3 was found to regulate Ipr1 expression by directly binding the interferon-stimulated response element motif of the Ipr1 promoter. Knockdown of Ipr1 decreased the expression of immunity-related GTPase family M member 1 (Irgm1), which plays critical roles in autophagy initiation. Irgm1 promoter characterization revealed a p53 motif in front of the transcription start site. P53 was found to participate in regulation of Irgm1 expression and IPR1-related effects on P53 stability by affecting interactions between ribosomal protein L11 (RPL11) and transformed mouse 3T3 cell double minute 2 (MDM2). Our results indicate that Ipr1 integrates cGAS-IRF3 with p53-modulated Irgm1 expression.

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