scholarly journals Principles and characteristics of biological assemblies in experimentally determined protein structures

2019 ◽  
Author(s):  
Qifang Xu ◽  
Roland L. Dunbrack

AbstractMore than half of all structures in the PDB are assemblies of two or more proteins, including both homooligomers and heterooligomers. Structural information on these assemblies comes from X-ray crystallography, NMR, and cryo-EM spectroscopy. The correct assembly in an X-ray structure is often ambiguous, and computational methods have been developed to identify the most likely biologically relevant assembly based on physical properties of assemblies and sequence conservation in interfaces. Taking advantage of the large number of structures now available, some of the most recent methods have relied on similarity of interfaces and assemblies across structures of homologous proteins.

2018 ◽  
Vol 19 (11) ◽  
pp. 3401 ◽  
Author(s):  
Ashutosh Srivastava ◽  
Tetsuro Nagai ◽  
Arpita Srivastava ◽  
Osamu Miyashita ◽  
Florence Tama

Protein structural biology came a long way since the determination of the first three-dimensional structure of myoglobin about six decades ago. Across this period, X-ray crystallography was the most important experimental method for gaining atomic-resolution insight into protein structures. However, as the role of dynamics gained importance in the function of proteins, the limitations of X-ray crystallography in not being able to capture dynamics came to the forefront. Computational methods proved to be immensely successful in understanding protein dynamics in solution, and they continue to improve in terms of both the scale and the types of systems that can be studied. In this review, we briefly discuss the limitations of X-ray crystallography in studying protein dynamics, and then provide an overview of different computational methods that are instrumental in understanding the dynamics of proteins and biomacromolecular complexes.


2021 ◽  
Author(s):  
Shanshan YC Bradford ◽  
Lea El Khoury ◽  
Yunhui Ge ◽  
Meghan Osato ◽  
David L. Mobley ◽  
...  

X-ray crystallography is the gold standard to resolve conformational ensembles that are significant for protein function, ligand discovery, and computational methods development. However, relevant conformational states may be missed at...


2009 ◽  
Vol 13 (01) ◽  
pp. 60-69 ◽  
Author(s):  
Jonathan P. Hill ◽  
Katsuhiko Ariga ◽  
Francis D'Souza

The structure and physical properties of a series of N-substituted, hemiquinone-substituted oxoporphyrinogens is presented and discussed. Structures of the compounds are dictated by the nature of the substituent, with the substitution pattern being in turn dictated by regioselectivity of N-alkylation. X-ray crystallography and other aggregation properties of the compounds are discussed. Redox reactions are also strongly influenced by N-substitution and substituent identity. Also presented are properties related to guest binding and photophysical properties of oligochromophoric host-guest complexes, involving oxoporphyrinogen, N-substituted with porphyrins and appropriately substituted fullerene guest electron acceptors.


2002 ◽  
Vol 30 (4) ◽  
pp. 521-525 ◽  
Author(s):  
O. S. Makin ◽  
L. C. Serpell

The pathogenesis of the group of diseases known collectively as the amyloidoses is characterized by the deposition of insoluble amyloid fibrils. These are straight, unbranching structures about 70–120 å (1 å = 0.1 nm) in diameter and of indeterminate length formed by the self-assembly of a diverse group of normally soluble proteins. Knowledge of the structure of these fibrils is necessary for the understanding of their abnormal assembly and deposition, possibly leading to the rational design of therapeutic agents for their prevention or disaggregation. Structural elucidation is impeded by fibril insolubility and inability to crystallize, thus preventing the use of X-ray crystallography and solution NMR. CD, Fourier-transform infrared spectroscopy and light scattering have been used in the study of the mechanism of fibril formation. This review concentrates on the structural information about the final, mature fibril and in particular the complementary techniques of cryo-electron microscopy, solid-state NMR and X-ray fibre diffraction.


Author(s):  
Zhenlu Li ◽  
Matthias Buck

Of 20,000 or so canonical human protein sequences, as of July 2020, 6,747 proteins have had their full or partial medium to high-resolution structures determined by x-ray crystallography or other methods. Which of these proteins dominate the protein database (the PDB) and why? In this paper, we list the 272 top protein structures based on the number of their PDB depositions. This set of proteins accounts for more than 40% of all available human PDB entries and represent past trend and current status for protein science. We briefly discuss the relationship which some of the prominent protein structures have with protein biophysics research and mention their relevance to human diseases. The information may inspire researchers who are new to protein science, but it also provides a year 2020 snap-shot for the state of protein science.


2018 ◽  
Vol 16 (02) ◽  
pp. 1840005 ◽  
Author(s):  
Dmitry Suplatov ◽  
Yana Sharapova ◽  
Daria Timonina ◽  
Kirill Kopylov ◽  
Vytas Švedas

The visualCMAT web-server was designed to assist experimental research in the fields of protein/enzyme biochemistry, protein engineering, and drug discovery by providing an intuitive and easy-to-use interface to the analysis of correlated mutations/co-evolving residues. Sequence and structural information describing homologous proteins are used to predict correlated substitutions by the Mutual information-based CMAT approach, classify them into spatially close co-evolving pairs, which either form a direct physical contact or interact with the same ligand (e.g. a substrate or a crystallographic water molecule), and long-range correlations, annotate and rank binding sites on the protein surface by the presence of statistically significant co-evolving positions. The results of the visualCMAT are organized for a convenient visual analysis and can be downloaded to a local computer as a content-rich all-in-one PyMol session file with multiple layers of annotation corresponding to bioinformatic, statistical and structural analyses of the predicted co-evolution, or further studied online using the built-in interactive analysis tools. The online interactivity is implemented in HTML5 and therefore neither plugins nor Java are required. The visualCMAT web-server is integrated with the Mustguseal web-server capable of constructing large structure-guided sequence alignments of protein families and superfamilies using all available information about their structures and sequences in public databases. The visualCMAT web-server can be used to understand the relationship between structure and function in proteins, implemented at selecting hotspots and compensatory mutations for rational design and directed evolution experiments to produce novel enzymes with improved properties, and employed at studying the mechanism of selective ligand’s binding and allosteric communication between topologically independent sites in protein structures. The web-server is freely available at https://biokinet.belozersky.msu.ru/visualcmat and there are no login requirements.


2014 ◽  
Vol 70 (a1) ◽  
pp. C1603-C1603
Author(s):  
Vijay Reddy ◽  
Glen Nemerow

Human adenoviruses (HAdVs) are large (~150nm in diameter, 150MDa) nonenveloped double-stranded DNA (dsDNA) viruses that cause respiratory, ocular, and enteric diseases. The capsid shell of adenovirus (Ad) comprises multiple copies of three major capsid proteins (MCP: hexon, penton base and fiber) and four minor/cement proteins (IIIa, VI, VIII and IX) that are organized with pseudo T=25 icosahedral symmetry. In addition, six other proteins (V, VII, μ, IVa2, terminal protein and protease) are encapsidated along with the 36Kb dsDNA genome inside the capsid. The crystal structures of all three MCPs are known and so is their organization in the capsid from prior X-ray crystallography and cryoEM analyses. However structures and locations of various cement proteins are of considerable debate. We have determined and refined the structure of an entire human adenovirus employing X-ray crystallpgraphic methods at 3.8Å resolution. Adenovirus cement proteins play crucial roles in virion assembly, disassembly, cell entry and infection. Based on the refined crystal structure of adenovirus, we have determined the structure of the cement protein VI, a key membrane-lytic molecule and its associations with proteins V and VIII, which together glue peripentonal hexons beneath vertex region and connect them to rest of the capsid. Following virion maturation, the cleaved N-terminal pro-peptide of VI is observed deep in the peripentonal hexon cavity, detached from the membrane-lytic domain. Furthermore, we have significantly revised the recent cryoEM models for proteins IIIa and IX and both are located on the capsid exterior. Together, the cement proteins exclusively stabilize the hexon shell, thus rendering penton vertices the weakest links of the adenovirus capsid. Adenovirus cement protein structures reveal the molecular basis of the maturation cleavage of VI that is needed for endosome rupture and delivery of the virion into cytoplasm.


2007 ◽  
Vol 63 (7) ◽  
pp. 780-792 ◽  
Author(s):  
Debora L. Makino ◽  
Agnes H. Henschen-Edman ◽  
Steven B. Larson ◽  
Alexander McPherson

2014 ◽  
Vol 223 (1) ◽  
pp. T9-T23 ◽  
Author(s):  
Frank Peelman ◽  
Lennart Zabeau ◽  
Kedar Moharana ◽  
Savvas N Savvides ◽  
Jan Tavernier

Leptin plays a central role in the control of body weight and energy homeostasis, but is a pleiotropic cytokine with activities on many peripheral cell types. In this review, we discuss the interaction of leptin with its receptor, and focus on the structural and mechanistic aspects of the extracellular aspects of leptin receptor (LR) activation. We provide an extensive overview of all structural information that has been obtained for leptin and its receptor via X-ray crystallography, electron microscopy, small-angle X-ray scattering, homology modeling, and mutagenesis studies. The available knowledge is integrated into putative models toward a recapitulation of the LR activation mechanism.


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