Abstract:
:Helicobacter pylori VacA, a pore-forming toxin secreted by an autotransporter pathway, causes multiple alterations in human cells, contributes to the pathogenesis of peptic ulcer disease and gastric cancer, and is a candidate antigen for inclusion in an H. pylori vaccine. Here, we present a 2.4-A crystal structure of the VacA p55 domain, which has an important role in mediating VacA binding to host cells. The structure is predominantly a right-handed parallel beta-helix, a feature that is characteristic of autotransporter passenger domains but unique among known bacterial protein toxins. Notable features of VacA p55 include disruptions in beta-sheet contacts that result in five beta-helix subdomains and a C-terminal domain that contains a disulfide bond. Analysis of VacA protein sequences from unrelated H. pylori strains, including m1 and m2 forms of VacA, allows us to identify structural features of the VacA surface that may be important for interactions with host receptors. Docking of the p55 structure into a 19-A cryo-EM map of a VacA dodecamer allows us to propose a model for how VacA monomers assemble into oligomeric structures capable of membrane channel formation.
journal_name
Proc Natl Acad Sci U S Aauthors
Gangwer KA,Mushrush DJ,Stauff DL,Spiller B,McClain MS,Cover TL,Lacy DBdoi
10.1073/pnas.0707447104subject
Has Abstractpub_date
2007-10-09 00:00:00pages
16293-8issue
41eissn
0027-8424issn
1091-6490pii
0707447104journal_volume
104pub_type
杂志文章abstract::We used a family-based cluster detection approach designed to localize significant rare disease-risk variants clusters within a region of interest to systematically search for schizophrenia (SCZ) susceptibility genes within 49 genomic loci previously implicated by de novo copy number variants. Using two independent wh...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1309475110
更新日期:2014-01-07 00:00:00
abstract::Figs (Ficus spp., Moraceae) and their pollinating wasps (Agaonidae, Chalcidoidea) constitute perhaps the most tightly integrated pollination mutualism that is known. Figs are characterized by extraordinarily high global and local species diversity. It has been proposed that the diversification of this mutualism has oc...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章,评审
doi:10.1073/pnas.0501840102
更新日期:2005-05-03 00:00:00
abstract::Cellular imbalance in the levels of antioxidants and reactive oxygen species resulting in apoptosis is directly associated with a number of parasitic infections, aging, and several genetic and multifactorial diseases. The baculovirus AcNPV-encoded antiapoptotic p35 gene prevents apoptosis induced by a variety of apopt...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.96.9.4838
更新日期:1999-04-27 00:00:00
abstract::Ca2+-induced inhibition of alpha1C voltage-gated Ca2+ channels is a physiologically important regulatory mechanism that shortens the mean open time of these otherwise long-lasting high-voltage-activated channels. The mechanism of action of Ca2+ has been a matter of some controversy, as previous studies have proposed t...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.96.5.2435
更新日期:1999-03-02 00:00:00
abstract::The molecular nature of the cell surface-cytoskeleton interaction in microvilli isolated from ascites 13762 rat mammary adenocarcinoma sublines with immobile (MAT-C1) and mobile (MAT-B1) receptors was investigated by extraction and fractionation studies on the microvillar membranes. Extraction of membranes from MAT-C1...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.80.2.430
更新日期:1983-01-01 00:00:00
abstract::In suspension cultures of mouse spleen cells, the addition of small amounts (1-100 ng) of a heterologous antigen to which the donor mice had been primed significantly increased the number of anti-sheep erythrocyte plaques appearing after stimulation with sheep erythrocytes. A similar addition to identical cultures fro...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.68.8.1665
更新日期:1971-08-01 00:00:00
abstract::Renal cells isolated from vitamin D-deficient chicks had an increased Na+-dependent phosphate uptake when preincubated with 1,25-dihydroxycholecalciferol [1,25-(OH)2D3]. Phosphate uptake in the absence of Na+ and methyl alpha-glucoside uptake dependent on Na+ were not affected. Phosphate uptake was stimulated 15% by 0...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.79.11.3532
更新日期:1982-06-01 00:00:00
abstract::Infectious vesicular stomatitis virus (VSV), the prototypic nonsegmented negative-strand RNA virus, was recovered from a full-length cDNA clone of the viral genome. Bacteriophage T7 RNA polymerase expressed from a recombinant vaccinia virus was used to drive the synthesis of a genome-length positive-sense transcript o...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.92.18.8388
更新日期:1995-08-29 00:00:00
abstract::Membraneless organelles contain a wide spectrum of molecular chaperones, indicating their important roles in modulating the metastable conformation and biological function of membraneless organelles. Here we report that class I and II Hsp40 (DNAJ) proteins possess a high ability of phase separation rendered by the fle...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.2002437117
更新日期:2020-12-08 00:00:00
abstract::We have identified new genomic alterations in the breast cancer cell line HCC1954, using high-throughput transcriptome sequencing. With 120 Mb of cDNA sequences, we were able to identify genomic rearrangement events leading to fusions or truncations of genes including MRE11 and NSD1, genes already implicated in oncoge...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.0812945106
更新日期:2009-02-10 00:00:00
abstract::Interleukin 3 (IL-3) is a hematopoietic growth factor that supports the proliferation and differentiation of early hematopoietic-lineage progenitors. By using growth factor-dependent cell lines, IL-3 has been shown to induce the appearance of several phosphotyrosine-containing proteins, including a 140-kDa cell surfac...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.85.21.7982
更新日期:1988-11-01 00:00:00
abstract::Expression of the bacterial RecA protein in plants stimulates homologous recombination in tobacco. Here we show that RecA plays a direct role in DNA strand exchange in vivo. The number of sister chromatid exchanges (SCEs) was increased 2.4-fold over wild type in transgenic tobacco plants expressing a nuclear-targeted ...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.050582797
更新日期:2000-03-28 00:00:00
abstract::The flux of solvent water coupled to the transit of ions through protein pores is considerable. The effect of this electroosmotic solvent flow on the binding of a neutral molecule [beta-cyclodextrin (betaCD)] to sites within the staphylococcal alpha-hemolysin pore was investigated. Mutant alpha-hemolysin pores were us...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.2531778100
更新日期:2003-12-23 00:00:00
abstract::The perceptual color qualities of hue, saturation, and brightness do not correspond in any simple way to the physical characteristics of retinal stimuli, a fact that poses a major obstacle for any explanation of color vision. Here we test the hypothesis that these basic color attributes are determined by the statistic...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.0600890103
更新日期:2006-04-11 00:00:00
abstract::Viruses have been implicated in the development of neurodegenerative diseases, such as Alzheimer's, Parkinson's, and multiple sclerosis. Human herpesvirus-6 (HHV-6) is a neurotropic virus that has been associated with a wide variety of neurologic disorders, including encephalitis, mesial temporal lobe epilepsy, and mu...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1105143108
更新日期:2011-08-16 00:00:00
abstract::A somatic mutation in the X linked PIGA gene is responsible for the deficiency of glycosyl phosphatidylinositol (GPI)-anchored proteins on blood cells from patients with paroxysmal nocturnal hemoglobinuria. No inherited form of GPI-anchor deficiency has been described. Because conventional Piga gene knockout is associ...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.96.13.7479
更新日期:1999-06-22 00:00:00
abstract::Toll-like receptors (TLRs) are expressed on innate immune cells and trigger inflammation upon detection of pathogens and host tissue injury. TLR-mediated proinflammatory-signaling pathways are counteracted by partially characterized anti-inflammatory mechanisms that prevent exaggerated inflammation and host tissue dam...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1106232108
更新日期:2011-11-01 00:00:00
abstract::A natural (evolutionary) classification is provided for 242 basic helix-loop-helix (bHLH) motif-containing proteins. Phylogenetic analyses of amino acid sequences describe the patterns of evolutionary change within the motif and delimit evolutionary lineages. These evolutionary lineages represent well known functional...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.94.10.5172
更新日期:1997-05-13 00:00:00
abstract::A recently described organ culture system for human thymocytes is shown to support the generation of a diverse T-cell receptor repertoire in vitro: thymocytes of the alpha beta lineage, including representatives of the V beta families 5.2/5.3, 6.7, and 8, accounted for the majority of T-cell receptor-positive cells th...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.89.10.4255
更新日期:1992-05-15 00:00:00
abstract::Cumulative distributions of the number of doublings undergone by mixed megakaryocytic/erythroblastic colonies and by pure megakaryocytic colonies were determined from plasma clot cultures of bone marrow (from C57BL/6 mice) supplemented with erythropoietin. Analysis of these distributions suggests that these colonies a...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.79.14.4410
更新日期:1982-07-01 00:00:00
abstract::Climate models show that particles formed by nucleation can affect cloud cover and, therefore, the earth's radiation budget. Measurements worldwide show that nucleation rates in the atmospheric boundary layer are positively correlated with concentrations of sulfuric acid vapor. However, current nucleation theories do ...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1210285109
更新日期:2012-11-13 00:00:00
abstract::The Rhizobium common nod gene products NodABC are involved in the synthesis of the core lipochitooligosaccharide (Nod factor) structure, whereas the products of the host-specific nod genes are necessary for diverse structural modifications, which vary in different Rhizobium species. The sulfate group attached to the R...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.92.7.2706
更新日期:1995-03-28 00:00:00
abstract::Human workers ensure the functioning of governments around the world. The efficacy of human workers, in turn, is linked to the climatic conditions they face. Here we show that the same weather that amplifies human health hazards also reduces street-level government workers' oversight of these hazards. To do so, we emp...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1803765115
更新日期:2018-08-28 00:00:00
abstract::Traits that enable species to persist in ecological environments are often maintained over time, a phenomenon known as niche conservatism. Here we argue that ecological niches function at levels above species, notably at the level of genus for mammals, and that niche conservatism is also evident above the species leve...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.0901648106
更新日期:2009-11-17 00:00:00
abstract::We report a method for introducing mtDNA mutations into the mouse female germ line by means of embryonic stem (ES) cell cybrids. Mitochondria were recovered from the brain of a NZB mouse by fusion of synaptosomes to a mtDNA-deficient (rho degrees ) cell line. These cybrids were enucleated and the cytoplasts were elect...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.250491597
更新日期:2000-12-19 00:00:00
abstract::Methyl groups placed on varphiXsB1 replicative form DNA by the Escherichia coli B modification enzyme are located in the overlap between fragments Mbo II-3 and Alu I-2, a 61-base-pair DNA segment. Mutations that led to loss of susceptibility to restriction by E. coli B occurred within this segment at three positions s...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.75.5.2271
更新日期:1978-05-01 00:00:00
abstract::Three classes of heterogeneous nuclear RNA (HnRNA) alpha, beta, and gamma, with different chemical and physical properties, can be identified in the early sea urchin embryo by hybridization with poly(U). The relative amounts of these classes vary as a function of embryonic development. It is demonstrated here that the...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.74.6.2217
更新日期:1977-06-01 00:00:00
abstract::An unusual system of genetic exchange exists in the purple nonsulfur bacterium Rhodobacter capsulatus. DNA transmission is mediated by a small bacteriophage-like particle called the gene transfer agent (GTA) that transfers random 4.5-kb segments of the producing cell's genome to recipient cells, where allelic replacem...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.97.2.859
更新日期:2000-01-18 00:00:00
abstract::To test whether a 30S ribosomal subunitformylmethionyl-tRNA-mRNA complex is an obligatory intermediate in protein synthesis, 70S ribosomes from Escherichia coli were crosslinked with the bifunctional imidoester, dimethylsuberimidate. Crosslinked ribosomes contained covelently joined 30S and 50S subunits, as judged by ...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.69.12.3769
更新日期:1972-12-01 00:00:00
abstract::We examined the effect of the inhibition of initiation of DNA replication on the membrane association of the chromosomal origin of replication of Bacillus subtilis and the Staphylococcus aureus-Bacillus pumilus chimeric plasmid pSL103, using temperature-sensitive mutants of B. subtilis that have specifically affected ...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.77.5.2834
更新日期:1980-05-01 00:00:00