scholarly journals Crystal Structures ofSaccharomyces cerevisiae N-Myristoyltransferase with Bound Myristoyl-CoA and Inhibitors Reveal the Functional Roles of the N-terminal Region

2007 ◽  
Vol 282 (30) ◽  
pp. 22185-22194 ◽  
Author(s):  
Jian Wu ◽  
Yong Tao ◽  
Meilan Zhang ◽  
Michael H. Howard ◽  
Steven Gutteridge ◽  
...  
Keyword(s):  
Crystal Structures ◽  
Terminal Region ◽  
Functional Roles ◽  
Myristoyl Coa

scholarly journals Crystal structures of a [NiFe] hydrogenase large subunit HyhL in an immature state in complex with a Ni chaperone HypA

2018 ◽  
Vol 115 (27) ◽  
pp. 7045-7050 ◽  
Author(s):  
Sunghark Kwon ◽  
Satoshi Watanabe ◽  
Yuichi Nishitani ◽  
Takumi Kawashima ◽  
Tamotsu Kanai ◽  
...  
Keyword(s):  
Crystal Structures ◽  
Structure Analysis ◽  
Active Site ◽  
Cleavage Site ◽  
Large Subunit ◽  
Binding Domain ◽  
Terminal Region ◽  
Cluster Assembly ◽  
Unknown Mechanism ◽  
Mature Form

Ni-Fe clusters are inserted into the large subunit of [NiFe] hydrogenases by maturation proteins such as the Ni chaperone HypA via an unknown mechanism. We determined crystal structures of an immature large subunit HyhL complexed with HypA from Thermococcus kodakarensis. Structure analysis revealed that the N-terminal region of HyhL extends outwards and interacts with the Ni-binding domain of HypA. Intriguingly, the C-terminal extension of immature HyhL, which is cleaved in the mature form, adopts a β-strand adjacent to its N-terminal β-strands. The position of the C-terminal extension corresponds to that of the N-terminal extension of a mature large subunit, preventing the access of endopeptidases to the cleavage site of HyhL. These findings suggest that Ni insertion into the active site induces spatial rearrangement of both the N- and C-terminal tails of HyhL, which function as a key checkpoint for the completion of the Ni-Fe cluster assembly.

scholarly journals Molecular Mechanism Underlying Inhibition of Intrinsic ATPase Activity in a Ski2-like RNA Helicase

2019 ◽  
Author(s):  
Eva Absmeier ◽  
Karine F. Santos ◽  
Markus C. Wahl
Keyword(s):  
Water Molecule ◽  
Atpase Activity ◽  
Crystal Structures ◽  
Conformational Changes ◽  
Bound States ◽  
Molecular Mechanisms ◽  
Adenine Nucleotides ◽  
Rna Helicase ◽  
Terminal Region ◽  
List Type

SUMMARYRNA-dependent NTPases can act as RNA/RNA-protein remodeling enzymes and typically exhibit low NTPase activity in the absence of RNA/RNA-protein substrates. How futile intrinsic NTP hydrolysis is prevented is frequently not known. The ATPase/RNA helicase Brr2 belongs to the Ski2-like family of nucleic acid-dependent NTPases and is an integral component of the spliceosome. Comprehensive nucleotide binding and hydrolysis studies are not available for a member of the Ski2-like family. We present crystal structures of Chaetomium thermophilum Brr2 in the apo, ADP-bound and ATPyS-bound states, revealing nucleotide-induced conformational changes and a hitherto unknown ATPyS binding mode. Our results in conjunction with Brr2 structures in other molecular contexts reveal multiple molecular mechanisms that contribute to the inhibition of intrinsic ATPase activity, including an N-terminal region that restrains the RecA-like domains in an open conformation and exclusion of an attacking water molecule, and suggest how RNA substrate binding can lead to ATPase stimulation.HIGHLIGHTSCrystal structures of Brr2 in complex with different adenine nucleotides.The Brr2 N-terminal region counteracts conformational changes induced by ATP binding.Brr2 excludes an attacking water molecule in the absence of substrate RNA.Different helicase families resort to different NTPase mechanisms.

Structural and functional roles of the amino-terminal region and collagen-like domain of human serum mannan-binding protein

IUBMB Life ◽  
1996 ◽  
Vol 40 (5) ◽  
pp. 965-974
Author(s):  
Yong ◽  
Yasunori Yokota ◽  
Yasunori Kozutsumi ◽  
Toshisuke Kawasaki
Keyword(s):  
Human Serum ◽  
Binding Protein ◽  
Terminal Region ◽  
Functional Roles ◽  
Amino Terminal

scholarly journals Crystal structures reveal a thiol protease-like catalytic triad in the C-terminal region of Pasteurella multocida toxin

2007 ◽  
Vol 104 (12) ◽  
pp. 5139-5144 ◽  
Author(s):  
K. Kitadokoro ◽  
S. Kamitani ◽  
M. Miyazawa ◽  
M. Hanajima-Ozawa ◽  
A. Fukui ◽  
...  
Keyword(s):  
Crystal Structures ◽  
Pasteurella Multocida ◽  
Catalytic Triad ◽  
Terminal Region ◽  
Thiol Protease ◽  
Pasteurella Multocida Toxin

The Flexible C-Terminal Region of Aspergillus terreus Blasticidin S Deaminase: Identification of Its Functional Roles with Deletion Enzymes

2002 ◽  
Vol 290 (1) ◽  
pp. 421-426 ◽  
Author(s):  
Makoto Kimura ◽  
Makio Furuichi ◽  
Masaki Yamamoto ◽  
Takashi Kumasaka ◽  
Hiroshi Mizuno ◽  
...  
Keyword(s):  
Aspergillus Terreus ◽  
Terminal Region ◽  
Functional Roles ◽  
Blasticidin S

Pollutant Identification by Selected Area Electron Diffraction

1974 ◽  
Vol 32 ◽  
pp. 532-533
Author(s):  
R. E. Ferrell ◽  
G. G. Paulson ◽  
C. W. Walker
Keyword(s):  
Thermal Treatment ◽  
Electron Diffraction ◽  
Sample Preparation ◽  
Crystal Structures ◽  
Water Samples ◽  
Environmental Samples ◽  
Short Review ◽  
Selected Area Electron Diffraction ◽  
Multiple Component

Selected area electron diffraction (SAD) has been used successfully to determine crystal structures, identify traces of minerals in rocks, and characterize the phases formed during thermal treatment of micron-sized particles. There is an increased interest in the method because it has the potential capability of identifying micron-sized pollutants in air and water samples. This paper is a short review of the theory behind SAD and a discussion of the sample preparation employed for the analysis of multiple component environmental samples.

The Imaging of Crystal Structures and Crystal Defects

1978 ◽  
Vol 36 (3) ◽  
pp. 207-217
Author(s):  
J.M. Cowley
Keyword(s):  
Electron Microscope ◽  
Crystal Structures ◽  
Phase Contrast ◽  
Crystal Defects ◽  
Atom Density ◽  
Lack Of Information ◽  
Spatial Frequencies

The problem of "understandinq" electron microscope imaqes becomes more acute as the resolution is improved. The naive interpretation of an imaqe as representinq the projection of an atom density becomes less and less appropriate. We are increasinqly forced to face the complexities of coherent imaqinq of what are essentially phase objects. Most electron microscopists are now aware that, for very thin weakly scatterinq objects such as thin unstained bioloqical specimens, hiqh resolution imaqes are best obtained near the optimum defocus, as prescribed by Scherzer, where the phase contrast imaqe qives a qood representation of the projected potential, apart from a lack of information on the lower spatial frequencies. But phase contrast imaqinq is never simple except in idealized limitinq cases.

Transmission electron microscope studies in special ceramics

1978 ◽  
Vol 36 (1) ◽  
pp. 268-269
Author(s):  
A. Zangvil ◽  
L.J. Gauckler ◽  
G. Schneider ◽  
M. Rühle
Keyword(s):  
Phase Diagrams ◽  
Crystal Structures ◽  
Thin Foil ◽  
Limited Extent ◽  
Complex Materials ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Electron Microscopes ◽  
Lattice Resolution

The use of high temperature special ceramics which are usually complex materials based on oxides, nitrides, carbides and borides of silicon and aluminum, is critically dependent on their thermomechanical and other physical properties. The investigations of the phase diagrams, crystal structures and microstructural features are essential for better understanding of the macro-properties. Phase diagrams and crystal structures have been studied mainly by X-ray diffraction (XRD). Transmission electron microscopy (TEM) has contributed to this field to a very limited extent; it has been used more extensively in the study of microstructure, phase transformations and lattice defects. Often only TEM can give solutions to numerous problems in the above fields, since the various phases exist in extremely fine grains and subgrain structures; single crystals of appreciable size are often not available. Examples with some of our experimental results from two multicomponent systems are presented here. The standard ion thinning technique was used for the preparation of thin foil samples, which were then investigated with JEOL 200A and Siemens ELMISKOP 102 (for the lattice resolution work) electron microscopes.

Advancing the use of Voronoi–Dirichlet polyhedra to describe interactions in organic molecular crystal structures by the example of galunisertib polymorphs

CrystEngComm ◽  
2021 ◽  
Author(s):  
Viktor N. Serezhkin ◽  
Anton V. Savchenkov
Keyword(s):  
Crystal Structures ◽  
Molecular Crystal ◽  
Noncovalent Interactions ◽  
Organic Molecular Crystal ◽  
Universal Approach ◽  
Structure Properties

The universal approach for studying structure/properties relationships shows that every polymorph of galunisertib is characterized with unique noncovalent interactions.

Crystal structures of Magnaporthe oryzae trehalose-6-phosphate synthase (MoTps1) suggest a model for catalytic process of Tps1

2019 ◽  
Vol 476 (21) ◽  
pp. 3227-3240 ◽  
Author(s):  
Shanshan Wang ◽  
Yanxiang Zhao ◽  
Long Yi ◽  
Minghe Shen ◽  
Chao Wang ◽  
...  
Keyword(s):  
Crystal Structures ◽  
Conformational Changes ◽  
Magnaporthe Oryzae ◽  
Structural Information ◽  
Complex Structure ◽  
Critical Role ◽  
Catalytic Process ◽  
Structural Basis ◽  
Salt Bridges ◽  
Terminal Domain

Trehalose-6-phosphate (T6P) synthase (Tps1) catalyzes the formation of T6P from UDP-glucose (UDPG) (or GDPG, etc.) and glucose-6-phosphate (G6P), and structural basis of this process has not been well studied. MoTps1 (Magnaporthe oryzae Tps1) plays a critical role in carbon and nitrogen metabolism, but its structural information is unknown. Here we present the crystal structures of MoTps1 apo, binary (with UDPG) and ternary (with UDPG/G6P or UDP/T6P) complexes. MoTps1 consists of two modified Rossmann-fold domains and a catalytic center in-between. Unlike Escherichia coli OtsA (EcOtsA, the Tps1 of E. coli), MoTps1 exists as a mixture of monomer, dimer, and oligomer in solution. Inter-chain salt bridges, which are not fully conserved in EcOtsA, play primary roles in MoTps1 oligomerization. Binding of UDPG by MoTps1 C-terminal domain modifies the substrate pocket of MoTps1. In the MoTps1 ternary complex structure, UDP and T6P, the products of UDPG and G6P, are detected, and substantial conformational rearrangements of N-terminal domain, including structural reshuffling (β3–β4 loop to α0 helix) and movement of a ‘shift region' towards the catalytic centre, are observed. These conformational changes render MoTps1 to a ‘closed' state compared with its ‘open' state in apo or UDPG complex structures. By solving the EcOtsA apo structure, we confirmed that similar ligand binding induced conformational changes also exist in EcOtsA, although no structural reshuffling involved. Based on our research and previous studies, we present a model for the catalytic process of Tps1. Our research provides novel information on MoTps1, Tps1 family, and structure-based antifungal drug design.

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