Results
- Showing results for:
- Reset all filters
Search results
-
Journal articleFilloux A, 2011, , Frontiers in Microbiology, Vol: 2, ISSN: 1664-302X
Protein secretion systems are molecular nanomachines used by Gram-negative bacteria to thrive within their environment. They are used to release enzymes that hydrolyze complex carbon sources into usable compounds, or to release proteins that capture essential ions such as iron. They are also used to colonize and survive within eukaryotic hosts, causing acute or chronic infections, subverting the host cell response and escaping the immune system. In this article, the opportunistic human pathogen Pseudomonas aeruginosa is used as a model to review the diversity of secretion systems that bacteria have evolved to achieve these goals. This diversity may result from a progressive transformation of cell envelope complexes that initially may not have been dedicated to secretion. The striking similarities between secretion systems and type IV pili, flagella, bacteriophage tail, or efflux pumps is a nice illustration of this evolution. Differences are also needed since various secretion configurations call for diversity. For example, some proteins are released in the extracellular medium while others are directly injected into the cytosol of eukaryotic cells. Some proteins are folded before being released and transit into the periplasm. Other proteins cross the whole cell envelope at once in an unfolded state. However, the secretion system requires conserved basic elements or features. For example, there is a need for an energy source or for an outer membrane channel. The structure of this review is thus quite unconventional. Instead of listing secretion types one after each other, it presents a melting pot of concepts indicating that secretion types are in constant evolution and use basic principles. In other words, emergence of new secretion systems could be predicted the way Mendeleïev had anticipated characteristics of yet unknown elements.
-
Journal articleLuther PK, Winkler H, Taylor K, et al., 2011, , PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA, Vol: 108, Pages: 11423-11428, ISSN: 0027-8424
- Cite
- Citations: 138
-
Journal articleSedoud A, Cox N, Sugiura M, et al., 2011, , Biochemistry, Vol: 50, Pages: 6012-6021
The quinone-iron complex of the electron acceptor complex of Photosystem II was studied by EPR spectroscopy in Thermosynechococcus elongatus. New g ∼ 2 features belonging to the EPR signal of the semiquinone forms of the primary and secondary quinone, i.e., Q(A)(•-)Fe(2+) and Q(B)(•-)Fe(2+), respectively, are reported. In previous studies, these signals were missed because they were obscured by the EPR signal arising from the stable tyrosyl radical, TyrD(•). When the TyrD(•) signal was removed, either by chemical reduction or by the use of a mutant lacking TyrD, the new signals dominated the spectrum. For Q(A)(•-)Fe(2+), the signal was formed by illumination at 77 K or by sodium dithionite reduction in the dark. For Q(B)(•-)Fe(2+), the signal showed the characteristic period-of-two variations in its intensity when generated by a series of laser flashes. The new features showed relaxation characteristics comparable to those of the well-known features of the semiquinone-iron complexes and showed a temperature dependence consistent with an assignment to the low-field edge of the ground state doublet of the spin system. Spectral simulations are consistent with this assignment and with the current model of the spin system. The signal was also present in Q(B)(•-)Fe(2+) in plant Photosystem II, but in plants, the signal was not detected in the Q(A)(•-)Fe(2+) state.
-
Journal articleSaridakis E, Khurshid S, Govada L, et al., 2011, , PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA, Vol: 108, Pages: 11081-11086, ISSN: 0027-8424
- Cite
- Citations: 117
-
Journal articleChen S, Beeby M, Murphy GE, et al., 2011,
Structural diversity of bacterial flagellar motors
, EMBO J., Vol: 30, Pages: 2972-2981 -
Journal articleSu J-H, Cox N, Ames W, et al., 2011, , BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS, Vol: 1807, Pages: 829-840, ISSN: 0005-2728
- Cite
- Citations: 73
-
Journal articleMikkelsen H, Sivaneson M, Filloux A, 2011, , ENVIRONMENTAL MICROBIOLOGY, Vol: 13, Pages: 1666-1681, ISSN: 1462-2912
- Cite
- Citations: 180
-
Journal articleHerrero C, Quaranta A, Leibl W, et al., 2011, , ENERGY & ENVIRONMENTAL SCIENCE, Vol: 4, Pages: 2353-2365, ISSN: 1754-5692
- Cite
- Citations: 97
-
Journal articleRamachandran PL, Lovett JE, Carl PJ, et al., 2011, , JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, Vol: 133, Pages: 9395-9404, ISSN: 0002-7863
- Cite
- Citations: 78
-
Journal articleHerrero C, Quaranta A, Protti S, et al., 2011, , CHEMISTRY-AN ASIAN JOURNAL, Vol: 6, Pages: 1335-1339, ISSN: 1861-4728
- Cite
- Citations: 23
-
Journal articleSage JT, Zhang Y, McGeehan J, et al., 2011,
Infrared protein crystallography
, Biochimica et Biophysica Acta (BBA) - Proteins & Proteomics, Vol: 1841, Pages: 760-777We consider the application of infrared spectroscopy to protein crystals, with particular emphasis on exploiting molecular orientation through polarization measurements on oriented single crystals. Infrared microscopes enable transmission measurements on individual crystals using either thermal or nonthermal sources, and can accommodate flow cells, used to measure spectral changes induced by exposure to soluble ligands, and cryostreams, used for measurements of flash-cooled crystals. Comparison of unpolarized infrared measurements on crystals and solutions probes the effects of crystallization and can enhance the value of the structural models refined from X-ray diffraction data by establishing solution conditions under which they are most relevant. Results on several proteins are consistent with similar equilibrium conformational distributions in crystal and solutions. However, the rates of conformational change are often perturbed. Infrared measurements also detect products generated by X-ray exposure, including CO2. Crystals with favorable symmetry exhibit infrared dichroism that enhances the synergy with X-ray crystallography. Polarized infrared measurements on crystals can distinguish spectral contributions from chemically similar sites, identify hydrogen bonding partners, and, in opportune situations, determine three-dimensional orientations of molecular groups. This article is part of a Special Issue entitled: Protein Structure and Function in the Crystalline State.
-
Journal articleGarcia-Caballero A, Gavira JA, Pineda-Molina E, et al., 2011, , CRYSTAL GROWTH & DESIGN, Vol: 11, Pages: 2112-2121, ISSN: 1528-7483
- Cite
- Citations: 12
-
Conference paperChoudhury HG, Cameron AD, Iwata S, et al., 2011,
<i>Escherichia coli</i> detoxification of chalcolgens by TehAB
, 36th FEBS Congress of the Biochemistry for Tomorrows Medicine, Publisher: WILEY-BLACKWELL, Pages: 101-101, ISSN: 1742-464X -
Journal articleMichoux F, Ahmad N, McCarthy J, et al., 2011, , PLANT BIOTECHNOLOGY JOURNAL, Vol: 9, Pages: 575-584, ISSN: 1467-7644
- Cite
- Citations: 32
-
Journal articleWong ARC, Pearson JS, Bright MD, et al., 2011, , MOLECULAR MICROBIOLOGY, Vol: 80, Pages: 1420-1438, ISSN: 0950-382X
- Cite
- Citations: 273
-
Journal articleReichmann NT, Gruendling A, 2011, , FEMS MICROBIOLOGY LETTERS, Vol: 319, Pages: 97-105, ISSN: 0378-1097
- Cite
- Citations: 147
-
Journal articleKafasla P, Lin H, Curry S, et al., 2011, , RNA, Vol: 17, Pages: 1120-1131, ISSN: 1355-8382
- Cite
- Citations: 30
-
Journal articleMachuca-Tzili LE, Buxton S, Thorpe A, et al., 2011, , DISEASE MODELS & MECHANISMS, Vol: 4, Pages: 381-392, ISSN: 1754-8403
- Cite
- Citations: 29
-
Journal articleRobinson KS, Clements A, Williams AC, et al., 2011, , ONCOGENE, Vol: 30, Pages: 2391-2400, ISSN: 0950-9232
- Cite
- Citations: 70
-
Journal articleBoehm M, Romero E, Reisinger V, et al., 2011, , JOURNAL OF BIOLOGICAL CHEMISTRY, Vol: 286, Pages: 14812-14819
- Cite
- Citations: 92
-
Journal articleNishi K, Ono T, Nakamura T, et al., 2011, , Journal of Biological Chemistry, Vol: 286, Pages: 14427-14434, ISSN: 1083-351X
Human α(1)-acid glycoprotein (hAGP) in serum functions as a carrier of basic drugs. In most individuals, hAGP exists as a mixture of two genetic variants, the F1*S and A variants, which bind drugs with different selectivities. We prepared a mutant of the A variant, C149R, and showed that its drug-binding properties were indistinguishable from those of the wild type. In this study, we determined the crystal structures of this mutant hAGP alone and complexed with disopyramide (DSP), amitriptyline (AMT), and the nonspecific drug chlorpromazine (CPZ). The crystal structures revealed that the drug-binding pocket on the A variant is located within an eight-stranded β-barrel, similar to that found in the F1*S variant and other lipocalin family proteins. However, the binding region of the A variant is narrower than that of the F1*S variant. In the crystal structures of complexes with DSP and AMT, the two aromatic rings of each drug interact with Phe-49 and Phe-112 at the bottom of the binding pocket. Although the structure of CPZ is similar to those of DSP and AMT, its fused aromatic ring system, which is extended in length by the addition of a chlorine atom, appears to dictate an alternative mode of binding, which explains its nonselective binding to the F1*S and A variant hAGPs. Modeling experiments based on the co-crystal structures suggest that, in complexes of DSP, AMT, or CPZ with the F1*S variant, Phe-114 sterically hinders interactions with DSP and AMT, but not CPZ.
-
Journal articleMasino L, Nicastro G, De Simone A, et al., 2011, , BIOPHYSICAL JOURNAL, Vol: 100, Pages: 2033-2042, ISSN: 0006-3495
- Cite
- Citations: 42
-
Journal articleRyan AJ, Chung C-W, Curry S, 2011, , BMC STRUCTURAL BIOLOGY, Vol: 11
- Cite
- Citations: 34
-
Journal articleSheppard C, Camara B, Shadrin A, et al., 2011, , JOURNAL OF MOLECULAR BIOLOGY, Vol: 407, Pages: 623-632, ISSN: 0022-2836
- Cite
- Citations: 10
-
Journal articleAttia M, Foerster A, Rachez C, et al., 2011, , JOURNAL OF MOLECULAR BIOLOGY, Vol: 407, Pages: 647-660, ISSN: 0022-2836
- Cite
- Citations: 35
-
Journal articleGrippon S, Zhao Q, Robinson T, et al., 2011, , Nucleic Acids Research, Vol: 39, Pages: 2593-2603, ISSN: 1362-4962
Mismatch uracil DNA glycosylase (Mug) fromEscherichia coli is an initiating enzyme in thebase-excision repair pathway. As with other DNAglycosylases, the abasic product is potentiallymore harmful than the initial lesion. Since Mug isknown to bind its product tightly, inhibitingenzyme turnover, understanding how Mug bindsDNA is of significance when considering how Muginteracts with downstream enzymes in the baseexcisionrepair pathway. We have demonstrateddifferential binding modes of Mug between its substrateand abasic DNA product using both band shiftand fluorescence anisotropy assays. Mug binds itsproduct cooperatively, and a stoichiometric analysisof DNA binding, catalytic activity and saltdependenceindicates that dimer formation is offunctional significance in both catalytic activity andproduct binding. This is the first report ofcooperativity in the uracil DNA glycosylase superfamilyof enzymes, and forms the basis of productinhibition in Mug. It therefore provides a new perspectiveon abasic site protection and the findingsare discussed in the context of downstream lesionprocessing and enzyme communication in the baseexcision repair pathway.
-
Journal articleChoudhury HG, Cameron AD, Iwata S, et al., 2011, , BIOCHEMICAL JOURNAL, Vol: 435, Pages: 85-91, ISSN: 0264-6021
- Cite
- Citations: 15
-
Journal articleSalgado PS, Yan R, Rowan F, et al., 2011, , ACTA CRYSTALLOGRAPHICA SECTION F-STRUCTURAL BIOLOGY COMMUNICATIONS, Vol: 67, Pages: 467-470
- Cite
- Citations: 3
-
Journal articlePetit SJ, Wise EL, Chambers JC, et al., 2011, , ARTERIOSCLEROSIS THROMBOSIS AND VASCULAR BIOLOGY, Vol: 31, Pages: 914-920, ISSN: 1079-5642
- Cite
- Citations: 17
-
Journal articlePearson JS, Riedmaier P, Marches O, et al., 2011, , MOLECULAR MICROBIOLOGY, Vol: 80, Pages: 219-230, ISSN: 0950-382X
- Cite
- Citations: 105
This data is extracted from the Web of Science and reproduced under a licence from Thomson Reuters. You may not copy or re-distribute this data in whole or in part without the written consent of the Science business of Thomson Reuters.