Abstract:
:HetR is an essential regulator of heterocyst development in cyanobacteria. Many mutations in HetR render Anabaena incapable of nitrogen fixation. The protein binds to a DNA palindrome upstream of hetP and other genes. We have determined the crystal structures of HetR complexed with palindromic DNA targets, 21, 23, and 29 bp at 2.50-, 3.00-, and 3.25-Å resolution, respectively. The highest-resolution structure shows fine details of specific protein-DNA interactions. The lower-resolution structures with longer DNA duplexes have similar interaction patterns and show how the flap domains interact with DNA in a sequence nonspecific fashion. Fifteen of 15 protein-DNA contacts predicted on the basis of the structure were confirmed by single amino acid mutations that abolished binding in vitro and complementation in vivo. A striking feature of the structure is the association of glutamate 71 from each subunit of the HetR dimer with three successive cytosines in each arm of the palindromic target, a feature that is conserved among all known heterocyst-forming cyanobacteria sequenced to date.
journal_name
Proc Natl Acad Sci U S Aauthors
Kim Y,Ye Z,Joachimiak G,Videau P,Young J,Hurd K,Callahan SM,Gornicki P,Zhao J,Haselkorn R,Joachimiak Adoi
10.1073/pnas.1305971110subject
Has Abstractpub_date
2013-05-07 00:00:00pages
E1716-23issue
19eissn
0027-8424issn
1091-6490pii
1305971110journal_volume
110pub_type
杂志文章abstract::Chromosomes condense during mitotic entry to facilitate their segregation. Condensation is typically assayed in fixed preparations, limiting analysis of contributing factors. Here, we describe a quantitative method to monitor condensation kinetics in living cells expressing GFP fused to a core histone. We demonstrate ...
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.0606993103
更新日期:2006-10-10 00:00:00
abstract::Activation of the phosphatidylinositol 3-kinase (PI3K)/AKT signaling pathway is a frequent occurrence in human cancers and a major promoter of chemotherapeutic resistance. Inhibition of one downstream target in this pathway, mTORC1, has shown potential to improve chemosensitivity. However, the mechanisms and genetic m...
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.0804821105
更新日期:2008-08-05 00:00:00
abstract::The maturation of 5S RNA in Escherichia coli is poorly understood. Although it is known that large precursors of 5S RNA accumulate in mutant cells lacking the endoribonuclease-RNase E, almost nothing is known about how the mature 5' and 3' termini of these molecules are generated. We have examined 5S RNA maturation in...
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.92.15.6883
更新日期:1995-07-18 00:00:00
abstract::Immunoglobulin- or multiple myeloma-associated amyloidosis has been distinguished by the tissue deposition of Congophilic, fibrillar protein consisting of light chains or light-chain fragments (AL amyloidosis). We now report the isolation and characterization of another form of immunoglobulin-associated amyloid obtain...
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.87.17.6542
更新日期:1990-09-01 00:00:00
abstract::A synthetic DNA based on the known amino acid sequence of the brain/gut peptide cholecystokinin (CCK) was synthesized. This DNA contained deoxyinosines at ambiguous codon positions and was used as a probe to isolate the CCK gene directly from a human genomic library. Nucleotide sequence analysis of the isolated gene 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.82.7.1931
更新日期:1985-04-01 00:00:00
abstract::Absorbance changes in untreated intact leaf discs, produced upon excitation with high-intensity red light, were shown to be due to the photooxidation of cytochrome b-559. At low intensities (<100 W/m2), photooxidation was almost undetectable. Photooxidation occurred with a half-time of 4.3 sec and an extent of 0.64 mo...
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.87.23.9295
更新日期:1990-12-01 00:00:00
abstract::Partial amino acid sequence has been determined for the cone, alpha' subunit of the bovine photoreceptor cyclic nucleotide phosphodiesterase (PDE) and deduced from nucleotide sequences of a partial cDNA clone. These sequences identify the alpha' subunit as the product of a gene that is distinct from those encoding 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.87.1.288
更新日期:1990-01-01 00:00:00
abstract::Modification by covalent attachment of polyethylene glycol (PEG) can reduce the immunogenicity and prolong the circulating life of proteins, but the utility of this approach for any protein is restricted by the number and distribution of PEG attachment sites (e.g., epsilon-amino groups of lysine residues). We have dev...
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.88.16.7185
更新日期:1991-08-15 00:00:00
abstract::Recent demonstrations of correlated low-frequency MRI signal variations between subregions of the spinal cord at rest in humans, similar to those found in the brain, suggest that such resting-state functional connectivity constitutes a common feature of the intrinsic organization of the entire central nervous system. ...
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.1424106112
更新日期:2015-05-12 00:00:00
abstract::Induction of differentiation and apoptosis in cancer cells through ligands of nuclear hormone receptors (NHRs) is a novel and promising approach to cancer therapy. All-trans-retinoic acid (ATRA), an RA receptor-specific NHR ligand, is now used for selective cancers. The NHR, peroxisome proliferator-activated receptor ...
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.95.15.8806
更新日期:1998-07-21 00:00:00
abstract::Many animals employ sex pheromones to find mating partners during their reproductive seasons. However, most sex pheromones of vertebrates remain to be identified. Over the past 20 years, steroids and prostaglandins have been identified as sex pheromones in several fishes. These pheromones are broadly termed "hormonal ...
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.0604340103
更新日期:2006-10-17 00:00:00
abstract::Information concerning the dynamics of river meandering is embedded in their planforms. Here, we focus on how bend skewing varies with increasing sinuosity, and how flow direction is embedded in bend skewing. It has often been thought that upstream-skewed bends are dominant within a sufficiently long reach. These bend...
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.1910874116
更新日期:2019-11-19 00:00:00
abstract::Although nanoparticle-protein conjugates have been synthesized for numerous applications, bioconjugation remains a challenge, often resulting in denaturation or loss of protein function. This is partly because the protein-nanoparticle interface is poorly understood, which impedes the use of nanoparticles in nanomedici...
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.0807299106
更新日期:2009-03-17 00:00:00
abstract::The complete soybean leghemoglobin lbc(3) gene was transferred into the legume Lotus corniculatus using an Agrobacterium rhizogenes vector system. Organ-specific expression of the soybean gene was observed in root nodules formed on regenerated transgenic plants after infection with Rhizobium loti. The primary transcri...
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.84.16.5754
更新日期:1987-08-01 00:00:00
abstract::The complete amino acid sequences of the variable regions of two human IgM anti-gamma globulins are reported. The two proteins, Sie and Wol, share idiotypic determinants that are distinct from those shared by the two previously sequenced IgM anti-gamma globulins, Lay and Pom [Capra, J. D. & Kehoe, J. M. (1974) Proc. N...
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.78.6.3799
更新日期:1981-06-01 00:00:00
abstract::The 2.1-A resolution crystal structure of wild-type green fluorescent protein and comparison of it with the recently determined structure of the Ser-65 --> Thr (S65T) mutant explains the dual wavelength absorption and photoisomerization properties of the wild-type protein. The two absorption maxima are caused by a cha...
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.94.6.2306
更新日期:1997-03-18 00:00:00
abstract::An excised patch of embryonic muscle membrane was used as a probe for measuring the release of acetylcholine (AcCho) from growing spinal neurons in Xenopus cell culture. The neuron was stimulated extracellularly at the soma, and the evoked AcCho release was monitored at the growth cone, along the neurite, and near 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.84.8.2540
更新日期:1987-04-01 00:00:00
abstract::Leucine analogs were tested in the Krebs II ascites cell-free translation system for the ability to inhibit preprotein cleavage by replacing leucine in nascent chains of bovine preprolactin, rat preprolactin, human placental prelactogen (pre-hPL), and pre-alpha subunit of human chorionic gonadotropin (alpha-hCG). In 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.77.3.1356
更新日期:1980-03-01 00:00:00
abstract::Renal excretion of water and major electrolytes exhibits a significant circadian rhythm. This functional periodicity is believed to result, at least in part, from circadian changes in secretion/reabsorption capacities of the distal nephron and collecting ducts. Here, we studied the molecular mechanisms underlying circ...
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.0904890106
更新日期:2009-09-22 00:00:00
abstract::We have isolated, by molecular cloning and genetic complementation of a listeriolysin-negative mutant, a gene required for the expression of this virulence factor in Listeria monocytogenes. The mutant strain SLCC53, which was nonhemolytic and avirulent, harbored a deletion of 450 base pairs located approximately 1500 ...
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.87.21.8336
更新日期:1990-11-01 00:00:00
abstract::A rigorous numerical test of a hypothetical mechanism of a molecular motor should model explicitly the diffusive motion of the motor's degrees of freedom as well as the transition rates between the motor's chemical states. We present such a Brownian dynamics, mechanochemcial model of the coarse-grain structure of 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.0908192106
更新日期:2009-10-27 00:00:00
abstract::An effective metabolism is essential to all living organisms, including the important human pathogen Staphylococcus aureus. To establish successful infection, S. aureus must scavenge nutrients and coordinate its metabolism for proliferation. Meanwhile, it also must produce an array of virulence factors to interfere wi...
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.1411077111
更新日期:2014-11-18 00:00:00
abstract::Glucocorticoids rapidly and completely inhibit intracellular plasminogen activator activity in rat hepatoma cells, as assayed by the solubilization of 125I-labeled fibrin. Experiments in which extracts of dexamethasone-treated cells are mixed with extracts of control cells demonstrate an inhibitor of protease activity...
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.75.12.6130
更新日期:1978-12-01 00:00:00
abstract::We have shown that a scanning transmission electron microscope with a high brightness field emission source is capable of obtaining better than 3 A resolution using 30 to 40 keV electrons. Elastic dark field images of single atoms of uranium and mercury are shown which demonstrate this fact as determined by a modified...
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.71.1.1
更新日期:1974-01-01 00:00:00
abstract::The symbiotic bacterium Wolbachia pipientis has been considered unique in its ability to cause multiple reproductive anomalies in its arthropod hosts. Here we report that an undescribed bacterium is vertically transmitted and associated with thelytokous parthenogenetic reproduction in Encarsia, a genus of parasitoid 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.221467498
更新日期:2001-10-23 00:00:00
abstract::Positive lower bounds for pseudo-differential operators with nonnegative symbols are derived; the bounds in particular yield subelliptic estimates for operators arising as sums of squares of vector fields. ...
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.76.12.6055
更新日期:1979-12-01 00:00:00
abstract::The N-methyl-d-aspartate (NMDA) glutamate receptor (NMDAR), long implicated in developmental plasticity, shows decay time kinetics that shorten postnatally as NR2A subunits are added to the receptor. Neither the mechanism nor immediate effect of this change is known. We studied developing NMDAR currents by using visua...
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.0335786100
更新日期:2003-02-04 00:00:00
abstract::Knowledge of vibratory patterns in the cochlea is crucial to understanding the stimulation of mechanosensory cells. Experiments to determine the motion of the cochlear partition and surrounding fluid are extremely challenging. As a result, the motion data are incomplete and often contradictory. The bending mechanism 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.0401395101
更新日期:2004-04-20 00:00:00
abstract::Ubiquitination, the crucial posttranslational modification that regulates the eukaryotic proteome, is carried out by a trio of enzymes, known as E1 [ubiquitin (Ub)-activating enzyme], E2 (Ub-conjugating enzyme), and E3 (Ub ligase). Although most E2s can work with any of the three mechanistically distinct classes of E3...
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.1705060114
更新日期:2017-08-08 00:00:00
abstract::Fatty acid compositions of phospholipids of heart, liver, kidney, aorta, and serum from rats having streptozotocin-induced diabetes were determined and compared with those of nondiabetic controls. Linoleic and dihomo-gamma-linolenic acids were increased whereas arachidonic acid was decreased in most tissues, suggestin...
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.80.8.2375
更新日期:1983-04-01 00:00:00