Abstract:
:The majority of bacteria in the natural environment live within the confines of a biofilm. The Gram-positive bacterium Bacillus subtilis forms biofilms that exhibit a characteristic wrinkled morphology and a highly hydrophobic surface. A critical component in generating these properties is the protein BslA, which forms a coat across the surface of the sessile community. We recently reported the structure of BslA, and noted the presence of a large surface-exposed hydrophobic patch. Such surface patches are also observed in the class of surface-active proteins known as hydrophobins, and are thought to mediate their interfacial activity. However, although functionally related to the hydrophobins, BslA shares no sequence nor structural similarity, and here we show that the mechanism of action is also distinct. Specifically, our results suggest that the amino acids making up the large, surface-exposed hydrophobic cap in the crystal structure are shielded in aqueous solution by adopting a random coil conformation, enabling the protein to be soluble and monomeric. At an interface, these cap residues refold, inserting the hydrophobic side chains into the air or oil phase and forming a three-stranded β-sheet. This form then self-assembles into a well-ordered 2D rectangular lattice that stabilizes the interface. By replacing a hydrophobic leucine in the center of the cap with a positively charged lysine, we changed the energetics of adsorption and disrupted the formation of the 2D lattice. This limited structural metamorphosis represents a previously unidentified environmentally responsive mechanism for interfacial stabilization by proteins.
journal_name
Proc Natl Acad Sci U S Aauthors
Bromley KM,Morris RJ,Hobley L,Brandani G,Gillespie RM,McCluskey M,Zachariae U,Marenduzzo D,Stanley-Wall NR,MacPhee CEdoi
10.1073/pnas.1419016112subject
Has Abstractpub_date
2015-04-28 00:00:00pages
5419-24issue
17eissn
0027-8424issn
1091-6490pii
1419016112journal_volume
112pub_type
杂志文章abstract::Homology-directed repair (HDR) is a critical pathway for the repair of DNA double-strand breaks (DSBs) in mammalian cells. Efficient HDR is thought to be crucial for maintenance of genomic integrity during organismal development and tumor suppression. However, most mammalian HDR studies have focused on transformed and...
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.1216824110
更新日期:2013-04-02 00:00:00
abstract::Extracts of insect cells infected with baculoviruses recombinant for the herpes simplex virus 1 (HSV-1)-encoded enzymes that are required for its replication can promote the rolling circle replication of circular plasmid templates. Replication is independent of a HSV-1 origin of replication (oris) or the HSV-1 origin ...
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.91.22.10665
更新日期:1994-10-25 00:00:00
abstract::Rare nucleated fetal cells circulate within maternal blood. Noninvasive prenatal diagnosis by isolation and genetic analysis of these cells is currently being undertaken. We sought to determine if genetic evidence existed for persistent circulation of fetal cells from prior pregnancies. Venous blood samples were obtai...
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.93.2.705
更新日期:1996-01-23 00:00:00
abstract::The pattern of antibody specificities in sera from patients with myasthenia gravis (MG) was determined by the ability of monoclonal antibodies against defined determinants on the acetylcholine receptor molecule to inhibit binding of the serum antibodies to receptor from human muscle. We found that MG patients produce ...
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.79.1.188
更新日期:1982-01-01 00:00:00
abstract::We have generated RANK (receptor activator of NF-kappaB) nullizygous mice to determine the molecular genetic interactions between osteoprotegerin, osteoprotegerin ligand, and RANK during bone resorption and remodeling processes. RANK(-/-) mice lack osteoclasts and have a profound defect in bone resorption and remodeli...
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.97.4.1566
更新日期:2000-02-15 00:00:00
abstract::Cells of the human embryonic stem (hES) cell line H9, when cultured in the form of embryoid bodies, give rise to cells with markers of the keratinocyte of stratified squamous epithelia. Keratinocytes also form in nodules produced in scid mice by injected H9 cells; the hES-derived keratinocytes could be recovered in cu...
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.0510953103
更新日期:2006-02-07 00:00:00
abstract::The genetic code in a eukaryotic system has been expanded by the engineering of Escherichia coli tyrosyl-tRNA synthetase (TyrRS) with the Y37V and Q195C mutations (37V195C), which specifically recognize 3-iodo-L-tyrosine rather than L-tyrosine. In the present study, we determined the 3-iodo-L-tyrosine- and L-tyrosine-...
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.0407039102
更新日期:2005-02-01 00:00:00
abstract::Recombinant plasmids containing mutant or wild-type adenovirus serotype 2 EIa genes that produce the 12S mRNA alone, the 13S mRNA alone, or both mRNAs were cotransfected into HeLa cells with plasmids containing the viral EIIa or EIII transcription units. The amount of RNA produced from the EIIa and EIII promoters was ...
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.81.14.4381
更新日期:1984-07-01 00:00:00
abstract::Although it is known that the human genome contains hundreds of microRNA (miRNA) genes and that each miRNA can regulate a large number of mRNA targets, the overall effect of miRNAs on mRNA tissue profiles has not been systematically elucidated. Here, we show that predicted human mRNA targets of several highly tissue-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.0511045103
更新日期:2006-02-21 00:00:00
abstract::Four cell types from Vicia faba Linnaeus "Long Pod" leaflets were assayed for three enzymes unique to the photosynthetic carbon reduction pathway. The enzymes were ribulosebisphosphate carboxylase [3-phospho-D-glycerate carboxy-lyase (dimerizing), EC 4.1.1.39], phosphoribulokinase (ATP:D-ribulose-5-phosphate 1-phospho...
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.76.12.6371
更新日期:1979-12-01 00:00:00
abstract::Natural products have long served as both a source and inspiration for pharmaceuticals. Modifying the structure of a natural product often improves the biological activity of the compound. Metabolic engineering strategies to ferment "unnatural" products have been enormously successful in microbial organisms. However, ...
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.0903393106
更新日期:2009-08-18 00:00:00
abstract::Three lines of evidence indicate that RNA-dependent RNA synthesis occurs in mouse erythroleukemia cells. The first involves labeling studies with [3H]uridine and shows a greater initial labeling rate of globin RNA in the cytoplasm than in the nucleus. Labeled globin RNA found in the cytoplasm after a very short pulse ...
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.83.5.1208
更新日期:1986-03-01 00:00:00
abstract::Metallophilicity is defined as the interaction among closed-shell metal centers, the origin of which remains controversial, particularly for the roles of spd orbital hybridization (mixing of the spd atomic orbitals of the metal atom in the molecular orbitals of metal complex) and the relativistic effect. Our studies 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.2019265118
更新日期:2021-01-05 00:00:00
abstract::The Hawaiian honeycreepers (Drepanidae) represent a superb illustration of evolutionary radiation, with a single colonization event giving rise to 19 extant and at least 10 extinct species [Curnutt, J. & Pimm, S. (2001) Stud. Avian Biol. 22, 15-30]. They also represent a dramatic example of anthropogenic extinction. C...
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.162372399
更新日期:2002-10-29 00:00:00
abstract::Saccharomyces cerevisiae has a complex system for switching the mating type of haploid cells, requiring the genome to have three mating-type (MAT)-like loci and a mechanism for silencing two of them. How this system originated is unknown, because the three-locus system is present throughout the family Saccharomycetace...
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.1416014111
更新日期:2014-11-11 00:00:00
abstract::We propose a model for DNA polymerase fidelity in which free energy differences, delta delta G, between matched and mismatched nucleotides are magnified at the enzyme's active site. Both hydrogen bonding and stacking components of the interaction energy are amplified, with the most profound effect being on the magnitu...
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.83.6.1559
更新日期:1986-03-01 00:00:00
abstract::Tyrosine phosphorylation of insulin receptor substrate-1 (IRS-1) by the insulin receptor permits this docking protein to interact with signaling proteins that promote insulin action. Serine phosphorylation uncouples IRS-1 from the insulin receptor, thereby inhibiting its tyrosine phosphorylation and insulin signaling....
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.051042298
更新日期:2001-04-10 00:00:00
abstract::Host-encoded factors play an important role in virus multiplication, acting in concert with virus-encoded factors. However, information regarding the host factors involved in this process is limited. Here we report the map-based cloning of an Arabidopsis thaliana gene, TOM1, which is necessary for the efficient multip...
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.170295097
更新日期:2000-08-29 00:00:00
abstract::Actin polymerization provides a powerful propulsion force for numerous types of cell motility. Although tremendous progress has been made in identifying the biochemical components necessary for actin-based motility, the precise biophysical mechanisms of force generation remain unclear. To probe the polymerization forc...
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.0837027100
更新日期:2003-04-15 00:00:00
abstract::Astrocyte-elevated gene-1 (AEG-1) expression is increased in multiple cancers and plays a central role in Ha-ras-mediated oncogenesis through the phosphatidylinositol 3-kinase (PI3K)/Akt signaling pathway. Additionally, overexpression of AEG-1 protects primary and transformed human and rat cells from serum starvation-...
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.0910936106
更新日期:2009-12-15 00:00:00
abstract::Knowing how motile bacteria move near and along a solid surface is crucial to understanding such diverse phenomena as the migration of infectious bacteria along a catheter, biofilm growth, and the movement of bacteria through the pore spaces of saturated soil, a critical step in the in situ bioremediation of contamina...
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.92.13.6195
更新日期:1995-06-20 00:00:00
abstract::The phytochrome family of informational photoreceptors has a central role in regulating light-responsive gene expression, but the mechanism of intracellular signal transduction has remained elusive. In a genetic screen for T DNA-tagged Arabidopsis mutants affected in early signaling intermediates, we identified poc1 (...
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.96.10.5832
更新日期:1999-05-11 00:00:00
abstract::The productivity of aquatic ecosystems depends on the supply of limiting nutrients. The invasion of the Laurentian Great Lakes, the world's largest freshwater ecosystem, by dreissenid (zebra and quagga) mussels has dramatically altered the ecology of these lakes. A key open question is how dreissenids affect the cycli...
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.2008223118
更新日期:2021-02-09 00:00:00
abstract::Accurate modification of the 3 billion-base-pair human genome requires tools with exceptional sequence specificity. Here, we describe a general strategy for the design of enzymes that target a single site within the genome. We generated chimeric zinc finger recombinases with cooperative DNA-binding and catalytic speci...
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.0812502106
更新日期:2009-03-31 00:00:00
abstract::By affinity chromatography on heparin-Sepharose, two classes of lipoproteins were separated from high density lipoproteins (HDL) isolated from patients with primary or secondary lecithin:cholesterol acyltransferase (LCATase; EC 2.3.1.43) deficiency and from normal subjects. The unretained fraction, HDL(A), was charact...
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.77.5.2969
更新日期:1980-05-01 00:00:00
abstract::Cyclization/cleavage of the 2-(p-nitrophenyl) phosphate ester of propylene glycol is catalyzed by imidazole and, much more effectively, by Zn2+ with imidazole. In the latter case, the mechanism involves simultaneous Lewis acid/base catalysis. Similar Zn2+ and imidazole catalysis of cyclization/cleavage is seen with 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.86.6.1746
更新日期:1989-03-01 00:00:00
abstract::Phosphorylation of the regulatory (R) domain initiates cystic fibrosis transmembrane conductance regulator (CFTR) Cl(-) channel activity. To discover how the function of this domain is determined by its structure, we produced an R domain protein (R8) that spanned residues 708-831 of CFTR. Phosphorylated, but not unpho...
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.100588797
更新日期:2000-05-09 00:00:00
abstract::Starburst polyamidoamine dendrimers are a new class of synthetic polymers with unique structural and physical characteristics. These polymers were investigated for the ability to bind DNA and enhance DNA transfer and expression in a variety of mammalian cell lines. Twenty different types of polyamidoamine dendrimers w...
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.93.10.4897
更新日期:1996-05-14 00:00:00
abstract::The DEMETER (DME) DNA glycosylase initiates active DNA demethylation via the base-excision repair pathway and is vital for reproduction in Arabidopsis thaliana DME-mediated DNA demethylation is preferentially targeted to small, AT-rich, and nucleosome-depleted euchromatic transposable elements, influencing expression ...
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.1620592114
更新日期:2017-02-21 00:00:00
abstract::The onset of autoimmunity in experimental rodent models and patients frequently correlates with a lymphopenic state. In this condition, the immune system has evolved compensatory homeostatic mechanisms that induce quiescent naive T cells to proliferate and differentiate into memory-like lymphocytes even in the apparen...
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.0807743105
更新日期:2008-12-09 00:00:00