scholarly journals Human Bocavirus Capsid Structure: Insights into the Structural Repertoire of the Parvoviridae

2010 ◽  
Vol 84 (12) ◽  
pp. 5880-5889 ◽  
Author(s):  
Brittney L. Gurda ◽  
Kristin N. Parent ◽  
Heather Bladek ◽  
Robert S. Sinkovits ◽  
Michael A. DiMattia ◽  
...  
Keyword(s):  
Parvovirus B19 ◽  
Three Dimensional ◽  
Surface Topology ◽  
Dimensional Structure ◽  
Human Bocavirus ◽  
Dna Viruses ◽  
Variable Surface ◽  
Antigenic Properties ◽  
Α Helix ◽  
Tract Infections

ABSTRACT Human bocavirus (HBoV) was recently discovered and classified in the Bocavirus genus (family Parvoviridae, subfamily Parvovirinae) on the basis of genomic similarity to bovine parvovirus and canine minute virus. HBoV has been implicated in respiratory tract infections and gastroenteric disease in children worldwide, yet despite numerous epidemiological reports, there has been limited biochemical and molecular characterization of the virus. Reported here is the three-dimensional structure of recombinant HBoV capsids, assembled from viral protein 2 (VP2), at 7.9-Å resolution as determined by cryo-electron microscopy and image reconstruction. A pseudo-atomic model of HBoV VP2 was derived from sequence alignment analysis and knowledge of the crystal structure of human parvovirus B19 (genus Erythrovirus). Comparison of the HBoV capsid structure to that of parvoviruses from five separate genera demonstrates strong conservation of a β-barrel core domain and an α-helix, from which emanate several loops of various lengths and conformations, yielding a unique surface topology that differs from the three already described for this family. The highly conserved core is consistent with observations for other single-stranded DNA viruses, and variable surface loops have been shown to confer the host-specific tropism and the diverse antigenic properties of this family.

scholarly journals Conformation and membrane interaction studies of the potent antimicrobial and anticancer peptide palustrin-Ca

2021 ◽  
Author(s):  
Patrick Brendan Timmons ◽  
Chandralal M Hewage
Keyword(s):  
Sodium Dodecyl ◽  
Three Dimensional ◽  
Dynamics Simulation ◽  
Peptide Sequence ◽  
Helical Conformation ◽  
Dimensional Structure ◽  
Amino Acid Residues ◽  
Anticancer Activities ◽  
American Bullfrog ◽  
Α Helix

Palustrin-Ca (GFLDIIKDTGKEFAVKILNNLKCKLAGGCPP) is a host defense peptide with potent antimicrobial and anticancer activities, first isolated from the skin of the American bullfrog Lithobates catesbeianus. The peptide is 31 amino acid residues long, cationic and amphipathic. Two-dimensional NMR spectroscopy was employed to characterise its three-dimensional structure in a 50/50% water/2,2,2-trifluoroethanol-d3 mixture. The structure is defined by an α-helix that spans between Ile6-Ala26, and a cyclic disulphide bridged domain at the C-terminal end of the peptide sequence, between residues 23 and 29. A molecular dynamics simulation was employed to model the peptide's interactions with sodium dodecyl sulphate micelles, a widely used bacterial membrane-mimicking environment. Throughout the simulation, the peptide was found to maintain its α-helical conformation between residues Ile6-Ala26, while adopting a position parallel to the surface to micelle, which is energetically-favourable due to many hydrophobic and electrostatic contacts with the micelle.

scholarly journals Evolutionary conservation of the intrinsic disorder-based Radical-Induced Cell Death1 hub interactome

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Lise Friis Christensen ◽  
Lasse Staby ◽  
Katrine Bugge ◽  
Charlotte O’Shea ◽  
Birthe B. Kragelund ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Stress Responses ◽  
Plant Stress ◽  
Three Dimensional ◽  
Intrinsic Disorder ◽  
Dimensional Structure ◽  
Linear Motif ◽  
Intrinsically Disordered ◽  
Helix Formation ◽  
Α Helix

AbstractRadical-Induced Cell Death1 (RCD1) functions as a cellular hub interacting with intrinsically disordered transcription factor regions, which lack a well-defined three-dimensional structure, to regulate plant stress. Here, we address the molecular evolution of the RCD1-interactome. Using bioinformatics, its history was traced back more than 480 million years to the emergence of land plants with the RCD1-binding short linear motif (SLiM) identified from mosses to flowering plants. SLiM variants were biophysically verified to be functional and to depend on the same RCD1 residues as the DREB2A transcription factor. Based on this, numerous additional members may be assigned to the RCD1-interactome. Conservation was further strengthened by similar intrinsic disorder profiles of the transcription factor homologs. The unique structural plasticity of the RCD1-interactome, with RCD1-binding induced α-helix formation in DREB2A, but not detectable in ANAC046 or ANAC013, is apparently conserved. Thermodynamic analysis also indicated conservation with interchangeability between Arabidopsis and soybean RCD1 and DREB2A, although with fine-tuned co-evolved binding interfaces. Interruption of conservation was observed, as moss DREB2 lacked the SLiM, likely reflecting differences in plant stress responses. This whole-interactome study uncovers principles of the evolution of SLiM:hub-interactions, such as conservation of α-helix propensities, which may be paradigmatic for disorder-based interactomes in eukaryotes.

scholarly journals Ribokinase fromLeishmania donovani: purification, characterization and X-ray crystallographic analysis

2018 ◽  
Vol 74 (2) ◽  
pp. 99-104 ◽  
Author(s):  
Santhosh Gatreddi ◽  
Sayanna Are ◽  
Insaf Ahmed Qureshi
Keyword(s):  
Functional Characterization ◽  
Three Dimensional ◽  
Protozoan Parasite ◽  
Crystallographic Analysis ◽  
Size Exclusion ◽  
Dimensional Structure ◽  
Diffusion Method ◽  
Gene Encoding ◽  
Cell Parameters ◽  
Α Helix

Leishmaniais an auxotrophic protozoan parasite which acquires D-ribose by transporting it from the host cell and also by the hydrolysis of nucleosides. The enzyme ribokinase (RK) catalyzes the first step of ribose metabolism by phosphorylating D-ribose using ATP to produce D-ribose-5-phosphate. To understand its structure and function, the gene encoding RK fromL. donovaniwas cloned, expressed and purified using affinity and size-exclusion chromatography. Circular-dichroism spectroscopy of the purified protein showed comparatively more α-helix in the secondary-structure content, and thermal unfolding revealed theTmto be 317.2 K. Kinetic parameters were obtained by functional characterization ofL. donovaniRK, and theKmvalues for ribose and ATP were found to be 296 ± 36 and 116 ± 9.0 µM, respectively. Crystals obtained by the hanging-drop vapour-diffusion method diffracted to 1.95 Å resolution and belonged to the hexagonal space groupP61, with unit-cell parametersa=b= 100.25,c= 126.77 Å. Analysis of the crystal content indicated the presence of two protomers in the asymmetric unit, with a Matthews coefficient (VM) of 2.45 Å3 Da−1and 49.8% solvent content. Further study revealed that human counterpart of this protein could be used as a template to determine the first three-dimensional structure of the RK from trypanosomatid parasites.

scholarly journals Solution structure of the strawberry allergen Fra a 1

2012 ◽  
Vol 32 (6) ◽  
pp. 567-575 ◽  
Author(s):  
Christian Seutter von Loetzen ◽  
Kristian Schweimer ◽  
Wilfried Schwab ◽  
Paul Rösch ◽  
Olivia Hartl-Spiegelhauer
Keyword(s):  
Solution Structure ◽  
Three Dimensional ◽  
Protein Family ◽  
Dimensional Structure ◽  
Hydrophobic Pocket ◽  
Pigment Synthesis ◽  
Family Protein ◽  
Pr10 Protein ◽  
Α Helix

The PR10 family protein Fra a 1E from strawberry (Fragaria x ananassa) is down-regulated in white strawberry mutants, and transient RNAi (RNA interference)-mediated silencing experiments confirmed that Fra a 1 is involved in fruit pigment synthesis. In the present study, we determined the solution structure of Fra a 1E. The protein fold is identical with that of other members of the PR10 protein family and consists of a seven-stranded antiparallel β-sheet, two short V-shaped α-helices and a long C-terminal α-helix that encompass a hydrophobic pocket. Whereas Fra a 1E contains the glycine-rich loop that is highly conserved throughout the protein family, the volume of the hydrophobic pocket and the size of its entrance are much larger than expected. The three-dimensional structure may shed some light on its physiological function and may help to further understand the role of PR10 proteins in plants.

scholarly journals High-Resolution Structure of the Nuclease Domain of the Human Parvovirus B19 Main Replication Protein NS1

2021 ◽  
Author(s):  
Nancy Horton ◽  
Jonathan L Sanchez ◽  
Niloofar Ghadirian
Keyword(s):  
Dna Cleavage ◽  
Parvovirus B19 ◽  
Three Dimensional ◽  
Replication Protein ◽  
Dimensional Structure ◽  
Sequence Variant ◽  
Human Parvovirus B19 ◽  
Origin Of Replication ◽  
Viral Origin ◽  
Double Stranded Dna

Two new structures of the N-terminal domain of the main replication protein, NS1, of Human Parvovirus B19 (B19V) are presented. This domain (NS1-nuc) plays an important role in the “rolling hairpin” replication of the single-stranded B19V DNA genome, recognizing origin of replication sequences in double-stranded DNA, and cleaving (i.e. nicking) single-stranded DNA at a nearby site known as the trs. One structure of NS1-nuc is solved to 2.4 Å and shows the positions of two bound phosphate ions. A second structure shows the position of a single divalent cation in the DNA nicking active site. The three-dimensional structure of NS1-nuc is well conserved between the two forms, as well as with a previously solved structure of a sequence variant of the same domain, however shown here at significantly higher resolution. Using structures of NS1-nuc homologues bound to single- and double-stranded DNA, models for DNA recognition and nicking by B19V NS1-nuc are presented which predict residues important for DNA cleavage and for sequence specific recognition at the viral origin of replication.

scholarly journals Structural insights into the cause of human RSPH4A primary ciliary dyskinesia

2021 ◽  
pp. mbc.E20-12-0806
Author(s):  
Yanhe Zhao ◽  
Justine Pinskey ◽  
Jianfeng Lin ◽  
Weining Yin ◽  
Patrick R. Sears ◽  
...  
Keyword(s):  
Primary Ciliary Dyskinesia ◽  
Electron Tomography ◽  
Three Dimensional ◽  
Dimensional Structure ◽  
Structural Basis ◽  
Radial Spoke ◽  
Radial Spokes ◽  
Cilia And Flagella ◽  
Tract Infections ◽  
Ciliary Dyskinesia

Cilia and flagella are evolutionarily conserved eukaryotic organelles involved in cell motility and signaling. In humans, mutations in Radial Spoke Head Protein 4 homolog A ( RSPH4A) can lead to primary ciliary dyskinesia (PCD), a life-shortening disease characterized by chronic respiratory tract infections, abnormal organ positioning, and infertility. Despite its importance for human health, the location of RSPH4A in human cilia has not been resolved, and the structural basis of RSPH4A-/- PCD remains elusive. Here, we present the native, three-dimensional structure of RSPH4A-/- human respiratory cilia using samples collected non-invasively from a PCD patient. Using cryo-electron tomography and subtomogram averaging, we compared the structures of control and RSPH4A-/- cilia, revealing primary defects in two of the three radial spokes (RSs) within the axonemal repeat and secondary (heterogeneous) defects in the central pair complex. Similar to RSPH1-/- cilia, the radial spoke heads of RS1 and RS2, but not RS3, were missing in RSPH4A-/- cilia. However, RSPH4A-/- cilia also exhibited defects within the arch domains adjacent to the RS1 and RS2 heads, which were not observed with RSPH1 loss. Our results provide insight into the underlying structural basis for RSPH4A-/- PCD and highlight the benefits of applying cryo-ET directly to patient samples for molecular structure determination. [Media: see text]

scholarly journals The Structure of Bypass of Forespore C, an Intercompartmental Signaling Factor during Sporulation in Bacillus

2005 ◽  
Vol 280 (43) ◽  
pp. 36214-36220 ◽  
Author(s):  
Hayley M. Patterson ◽  
James A. Brannigan ◽  
Simon M. Cutting ◽  
Keith S. Wilson ◽  
Anthony J. Wilkinson ◽  
...  
Keyword(s):  
Rna Polymerase ◽  
Mother Cell ◽  
Asymmetric Cell Division ◽  
Three Dimensional ◽  
Dimensional Structure ◽  
Coat Proteins ◽  
Terminal Domain ◽  
Spore Coat Proteins ◽  
Α Helix ◽  
Β Sheet

Sporulation in Bacillus subtilis begins with an asymmetric cell division giving rise to smaller forespore and larger mother cell compartments. Different programs of gene expression are subsequently directed by compartment-specific RNA polymerase σ-factors. In the final stages, spore coat proteins are synthesized in the mother cell under the control of RNA polymerase containing σK, (EσK). σK is synthesized as an inactive zymogen, pro-σK, which is activated by proteolytic cleavage. Processing of pro-σK is performed by SpoIVFB, a metalloprotease that resides in a complex with SpoIVFA and bypass of forespore (Bof)A in the outer forespore membrane. Ensuring coordination of events taking place in the two compartments, pro-σK processing in the mother cell is delayed until appropriate signals are received from the forespore. Cell-cell signaling is mediated by SpoIVB and BofC, which are expressed in the forespore and secreted to the intercompartmental space where they regulate pro-σK processing by mechanisms that are not yet fully understood. Here we present the three-dimensional structure of BofC determined by solution state NMR. BofC is a monomer made up of two domains. The N-terminal domain, containing a four-stranded β-sheet onto one face of which an α-helix is packed, closely resembles the third immunoglobulin-binding domain of protein G from Streptococcus. The C-terminal domain contains a three-stranded β-sheet and three α-helices in a novel domain topology. The sequence connecting the domains contains a conserved DISP motif to which mutations that affect BofC activity map. Possible roles for BofC in the σK checkpoint are discussed in the light of sequence and structure comparisons.

scholarly journals N- and C-Terminal Cooperation in Rotavirus Enterotoxin: Novel Mechanism of Modulation of the Properties of a Multifunctional Protein by a Structurally and Functionally Overlapping Conformational Domain

2006 ◽  
Vol 80 (1) ◽  
pp. 412-425 ◽  
Author(s):  
M. R. Jagannath ◽  
M. M. Kesavulu ◽  
R. Deepa ◽  
P. Narayan Sastri ◽  
S. Senthil Kumar ◽  
...  
Keyword(s):  
Nonstructural Protein ◽  
Three Dimensional ◽  
Binding Activity ◽  
Dimensional Structure ◽  
Newborn Mouse ◽  
Multifunctional Protein ◽  
C Terminus ◽  
N Terminus ◽  
Α Helix ◽  
Pleiotropic Properties

ABSTRACT Rotavirus NSP4 is a multifunctional endoplasmic reticulum (ER)-resident nonstructural protein with the N terminus anchored in the ER and about 131 amino acids (aa) of the C-terminal tail (CT) oriented in the cytoplasm. Previous studies showed a peptide spanning aa 114 to 135 to induce diarrhea in newborn mouse pups with the 50% diarrheal dose approximately 100-fold higher than that for the full-length protein, suggesting a role for other regions in the protein in potentiating its diarrhea-inducing ability. In this report, employing a large number of methods and deletion and amino acid substitution mutants, we provide evidence for the cooperation between the extreme C terminus and a putative amphipathic α-helix located between aa 73 and 85 (AAH73-85) at the N terminus of ΔN72, a mutant that lacked the N-terminal 72 aa of nonstructural protein 4 (NSP4) from Hg18 and SA11. Cooperation between the two termini appears to generate a unique conformational state, specifically recognized by thioflavin T, that promoted efficient multimerization of the oligomer into high-molecular-mass soluble complexes and dramatically enhanced resistance against trypsin digestion, enterotoxin activity of the diarrhea-inducing region (DIR), and double-layered particle-binding activity of the protein. Mutations in either the C terminus, AAH73-85, or the DIR resulted in severely compromised biological functions, suggesting that the properties of NSP4 are subject to modulation by a single and/or overlapping highly sensitive conformational domain that appears to encompass the entire CT. Our results provide for the first time, in the absence of a three-dimensional structure, a unique conformation-dependent mechanism for understanding the NSP4-mediated pleiotropic properties including virus virulence and morphogenesis.

scholarly journals NMR resonance assignments of the four isoforms of the hazelnut allergen Cor a 1.04

2019 ◽  
Vol 14 (1) ◽  
pp. 45-49 ◽  
Author(s):  
Sebastian Führer ◽  
Ricarda Zeindl ◽  
Martin Tollinger
Keyword(s):  
Fruits And Vegetables ◽  
Chemical Shifts ◽  
Three Dimensional ◽  
Resonance Assignments ◽  
Subsequent Development ◽  
Dimensional Structure ◽  
Side Chain ◽  
Bet V 1 ◽  
Chemical Shift Data ◽  
Α Helix

Abstract In large parts of Europe, Northern America and China people are suffering from allergies after consuming certain kinds of fruits and vegetables. Typical allergic symptoms range from scratching and itching of the throat to severe symptoms like rhino conjunctivitis and anaphylaxis. For hazelnuts (Corylus avellana), these allergies result from initial sensitization to the birch (Betula verrucosa) pollen allergen Bet v 1 and subsequent development of allergic cross-reactions to proteins that are similar in their three-dimensional structure to the sensitizing protein Bet v 1. The cross-reactive proteins in hazelnut are the four isoforms Cor a 1.04 with a molecular weight of about 17.5 kDa. Significant differences regarding the immunologic behavior of these proteins have been reported. In this work we assigned backbone and side chain 1H, 13C, and 15N chemical shifts of these four isoforms, Cor a 1.0401, Cor a 1.0402, Cor a 1.0403, and Cor a 1.0404 by solution NMR spectroscopy. The chemical shift data confirm the characteristic Bet v onefold for all four isoforms, consisting of seven β-strands that are separated by two short α-helices, along with a long C-terminal α-helix. These data provide the basis for a comparative structural and dynamic analysis of these proteins by NMR in order to characterize their different immunologic cross-reactivities on a molecular level.

scholarly journals Biochemical features of parvovirus B19 genovariant 1a2 dominating during the incidence rise in Belarus

2020 ◽  
Vol 17 (2) ◽  
pp. 211-220
Author(s):  
M. A. Yermalovich ◽  
V. V. Khrustalev ◽  
T. A. Khrustaleva ◽  
V. V. Poboinev ◽  
E. O. Samoilovich
Keyword(s):  
Amino Acid ◽  
Parvovirus B19 ◽  
Three Dimensional ◽  
Amino Acid Sequences ◽  
Dimensional Structure ◽  
Amino Acid Substitutions ◽  
Structural Protein ◽  
Mutational Pressure ◽  
Amino Acid Variability ◽  
Unique Amino Acid

Two genovariants (1a1 and 1a2) are distinguished among Human parvovirus B19 (B19P) of subgenotype 1a, of which 1a2 was predominantly distributed during the incidence rise in Belarus. The aim of this study was a comparative analysis of the amino acid variability and of the mutational pressure directions in different parts of the genome between genovariants 1a1 and 1a2.The analysis of the consensus amino acid sequences of two genovariants and the three-dimensional structure models of protein fragments was carried out. In total, two unique amino acid substitutions in the main non-structural protein NS1 of 1a2 were found (I181M and E114G), one of which E114G is close to the DNA-binding domain (OBD) responsible for attachment to the replication origin site and can affect the rate of virus replication and transcription. Three unique amino acid substitutions were found in the structural polypeptide VP of 1a2: V30L, S98N, and N533S. Two of them are located in the most immunogenic region VP1u and can contribute to the escape from immune response. The investigation of the mutational pressure direction revealed a decrease in the frequency of G to T transversions in the second reading frame of 1a2, which reflects a higher transcription rate as a result of amino acid substitution in the OBD protein.The differences revealed between the genetic variants of subgenotype 1a B19P both in the antigenic sites and in the replication and transcription system can provide an increased “fitness” for the genetic variant 1a2 and explain its predominant distribution during the incidence rise.

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