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James R. Letts

1911 The Annals of Iowa  
She was interred in the city cemetery in Fort Madison, December 28, 1910. • JAMES R. LETTS was born in Licking county, Ohio, December 30, 1820; he died at Letts, Iowa, December 18, 1910.  ...  In the spring of 1876 he returned JAMES H. STODT was born in Dubuque, Iowa, September 25, 1848; he died at Menomonie, Wis., December 8, 1910.  ... 
doi:10.17077/0003-4827.3692 fatcat:iuz2632f6fgl5jg6wntbeu3pxe

Biophysical Studies of the Voltage-Dependent Proton Channel

Roderick MacKinnon, Joel Butterwick, James Letts Letts
2013 Biophysical Journal  
Support: NSF MCB-0943362, NIH R01-GM087507. 175-Symp Biophysical Studies of the Voltage-Dependent Proton Channel Roderick MacKinnon, Joel Butterwick, James Letts Letts.  ... 
doi:10.1016/j.bpj.2012.11.226 fatcat:2by5ps6wgzbrnpwyzdvn2i4sze

Triple major curves in children

Darin Davidson, Mervyn Letts, James Jarvis
2003 Canadian journal of surgery  
The predominant classification systems for scoliosis have been based either on etiology or curve pattern. Traditionally triple curves have not been included in either classification system. We reviewed the records of all children with an idiopathic triple scoliotic curve seen between 1988 and 2001 at the Children's Hospital of Eastern Ontario, Ottawa, a major pediatric referral centre. The triple curve had 3 structural curved segments in accordance with the classification of Lenke and
more » ... . Scoliosis was defined by a curve greater than 10 degrees, and the apical vertebra was determined according to Scoliosis Research Society guidelines. Laterality of the curve was determined from the curve with the greatest magnitude. Curve progression was an increase in magnitude of at least 5 degrees. Management included observation, with bracing if any curve progressed to greater than 20 degrees. Surgery was reserved for curves that were unstable, rapidly progressive and greater than 45 degrees-50 degrees. Thirteen children (9 girls, 4 boys) were treated for a triple scoliosis curve. The average age at the time the triple curve developed was 13 years and 9 months (range from 9 yr 1 mo-17 yr 5 mo). The average follow-up was 3 years and 6 months (range from 1-11 yr). One child required spinal fusion, and 6 years postoperatively the curve was stable with a good fusion mass. Of the remaining children, 2 were treated with an orthosis and 10 with observation. The triple major curve is a neglected curve pattern that should be included in classifications of scoliosis.
pmid:12812241 pmcid:PMC3211757 fatcat:73xjkfwkibgbpozzkexknaf3wa

Erratum: The 'pause' in global warming in historical context: II. Comparing models to observations (2018 Environ. Res. Lett. 13 123007)

Stephan Lewandowsky, Kevin Cowtan, James S Risbey, Michael E Mann, Byron A Steinman, Naomi Oreskes, Stefan Rahmstorf
2019 Environmental Research Letters  
Lett. 14 (2019) 049601 S Lewandowsky et al  ...  ORCID iDs Stephan Lewandowsky https:/ / James S Risbey https:/ / Stefan Rahmstorf https:/ / Values below 5% are circled  ... 
doi:10.1088/1748-9326/aafbb7 fatcat:ktxsdl2vtve4xbhfbtlyboqtrm

Cervical spine instability in children with Goldenhar's syndrome

David Healey, Merv Letts, James G Jarvis
2002 Canadian journal of surgery  
To study the vertebral involvement of the cervical spine, in particular the stability of C1-C2, in children with proven Goldenhar's syndrome. A case review. The Children's Hospital of Eastern Ontario, Ottawa. Eight children who had a minimum of 2 out of 3 Goldenhar criteria plus other strong associations with the syndrome and for whom detailed radiographic spinal assessment, including flexion-extension views of the cervical spine and computed tomography of the congenital anomalies, were
more » ... e. Radiographic findings. Seven children demonstrated cervical spine anomalies. Of particular concern was the high incidence of C1-C2 instability in 3 children, 2 of whom required occiput to C2 fusion. The presence of hemivertebrae and failures of segmentation were most common and resulted in thoracic scoliosis, leading to spinal fusion in 2 children. In patients with Goldenhar's syndrome the cervical spines must be monitored carefully for C1-C2 subluxation before any proposed surgery for other malformations associated with the syndrome, so that any instability can be identified to avoid cord impingement during a general anesthetic.
pmid:12387536 pmcid:PMC3684635 fatcat:g6m2jjyev5cmhoc3to3emub7da

Preliminary Structure/Function Studies of the Human Voltage-Gated Proton Channel

James A. Letts, Joel Butterwick, Rodderick MacKinnon
2013 Biophysical Journal  
A. 101: 4805-4809. 344-Pos Board B113 Preliminary Structure/Function Studies of the Human Voltage-Gated Proton Channel James A. Letts, Joel Butterwick, Rodderick MacKinnon.  ... 
doi:10.1016/j.bpj.2012.11.407 fatcat:6i37jm5dx5czdlrhc7pkn6uulq

Functional Reconstitution of Purified Human Hv1 H+ Channels

Seok-Yong Lee, James A. Letts, Roderick MacKinnon
2009 Journal of Molecular Biology  
Voltage-dependent H + (Hv) channels mediate proton conduction into and out of cells under the control of membrane voltage. Hv channels are unusual compared to voltage-dependent K + , Na + and Ca 2+ channels in that Hv channel genes encode a voltage sensor domain (VSD) without a pore domain. The H + currents observed when Hv channels are expressed heterologously suggest that the VSD itself provides the pathway for proton conduction. In order to exclude the possibility that the Hv channel VSD
more » ... mbles with an as yet unknown protein in the cell membrane as a requirement for H + conduction we have purified Hv channels to homogeneity and reconstituted them into synthetic lipid liposomes. The Hv channel VSD by itself supports H + flux. Keywords Voltage-sensor; Membrane protein; Proton channel Voltage-dependent H + (Hv) channels were first described in snail neurons and have been characterized most thoroughly in mammalian cells by DeCoursey 1; 2 . Hv channels are involved in many cellular functions including acid extrusion and charge compensation during the phagocyte respiratory burst 3 . The recent discovery of Hv channel genes demonstrated that they encode membrane proteins that are related in amino acid sequence to voltage sensor domains (VSD) of voltage-dependent cation channels 4; 5 . Voltage-dependent cation channels contain a single central pore surrounded by four VSDs, which regulate opening and closing of the pore 6; 7 . It was therefore interesting to observe that Hv channels appear to consist of a regulatory (voltage-sensor) domain without a pore, and yet, when expressed in mammalian cells, they produce voltage-dependent H + currents with pharmacological properties expected of native Hv channels 4; 5 . Functional expression of a gene in cells leaves open the possibility that an unknown component provided by the cell is necessary to support function. Stimulated by our interest in voltage sensor proteins our laboratory has been studying Hv channels using biochemical methods with the ultimate goal to determine the atomic structure. Our expression and purification studies enable us to test the functional competence of the Hv VSD-like protein in a completely defined reconstituted state 8 .
doi:10.1016/j.jmb.2009.02.034 pmid:19233200 pmcid:PMC2778278 fatcat:j3zh66o35rgormx7eo47cfdbzq

Atomic structure of a mitochondrial complex I intermediate from vascular plants

Maria Maldonado, Abhilash Padavannil, Long Zhou, Fei Guo, James A Letts
2020 eLife  
The spectroscopic NADH dehydrogenase activity assay was performed based on Huang et al., 2015; Letts et al., 2019 .  ...  Mammalian, yeast and bacterial homologues were obtained from Letts and Sazanov, 2015 . Additional BLASTp searches were performed wherever necessary.  ... 
doi:10.7554/elife.56664 pmid:32840211 fatcat:oqelehnasjau3f6p66xahrzhfe

Erratum: "Effect of size and roughness on light transmission in a Si/SiO2 waveguide: Experiments and model" [Appl. Phys. Lett. 77, 1617 (2000)]

Kevin K. Lee, Desmond R. Lim, Hsin-Chiao Luan, Anuradha Agarwal, James Foresi, Lionel C. Kimerling
2000 Applied Physics Letters  
doi:10.1063/1.1320897 fatcat:oezskkpm5fhadppkc3s4zhvkbm

Atomic structures of respiratory complex III2 , complex IV and supercomplex III2+IV from vascular plants [article]

James A Letts, Maria Maldonado, Fei Guo
2020 bioRxiv   pre-print
Mitochondrial complex III (CIII2) and complex IV (CIV), which can associate into a higher-order supercomplex (SC III2+IV), play key roles in respiration. However, structures of these plant complexes remain unknown. We present atomic models of CIII2, CIV and SC III2+IV from Vigna radiata determined by single-particle cryoEM. The structures reveal plant-specific differences in the MPP domain of CIII2 and define the subunit composition of CIV. Conformational heterogeneity analysis of CIII2
more » ... long-range, coordinated movements across the complex, as well as the motion of CIII2's iron-sulfur head domain. The CIV structure suggests that, in plants, proton translocation does not occur via the H-channel. The supercomplex interface differs significantly from that in yeast and bacteria in its interacting subunits, angle of approach and limited interactions in the mitochondrial matrix. These structures challenge long-standing assumptions about the plant complexes, generate new mechanistic hypotheses and allow for the generation of more selective agricultural inhibitors.
doi:10.1101/2020.08.30.274431 fatcat:muerp63ijrdvnhc65ms76jobc4

Exercise and the Treatment of Clinical Depression in Adults

Alisha L. Brosse, Erin S. Sheets, Heather S. Lett, James A. Blumenthal
2002 Sports Medicine  
This article critically reviews the evidence that exercise is effective in treating depression in adults. Depression is recognised as a mood state, clinical syndrome and psychiatric condition, and traditional methods for assessing depression (e.g. standard interviews, questionnaires) are described. In order to place exercise therapy into context, more established methods for treating clinical depression are discussed. Observational (e.g. cross-sectional and correlational) and interventional
more » ... ies of exercise are reviewed in healthy adults, those with comorbid medical conditions, and patients with major depression. Potential mechanisms by which exercise may reduce depression are described, and directions for future research in the area are suggested. The available evidence provides considerable support for the value of exercise in reducing depressive symptoms in both healthy and clinical populations. However, many studies have significant methodological limitations. Thus, more data from carefully conducted clinical trials are needed before exercise can be recommended as an alternative to more traditional, empirically validated pharmacological and behavioural therapies.
doi:10.2165/00007256-200232120-00001 pmid:12238939 fatcat:fjjjtmwsijezfhmbbg52lnkt7a

Atomic structure of the entire mammalian mitochondrial complex I

Karol Fiedorczuk, James A. Letts, Gianluca Degliesposti, Karol Kaszuba, Mark Skehel, Leonid A. Sazanov
2016 Nature  
Mitochondrial complex I plays a key role in cellular energy production by transferring electrons from NADH to ubiquinone coupled to proton translocation across the membrane1,2. It is the largest protein assembly of the respiratory chain with total mass of 970 kDa3. Here we present a nearly complete atomic structure of ovine mitochondrial complex I at 3.9 Å resolution, solved by cryo-electron microscopy aided by crosslinking/mass-spectrometry mapping. All 14 conserved core and 31
more » ... cific supernumerary subunits are resolved within the L-shaped molecule. The hydrophilic matrix arm harbours FMN and 8 iron-sulphur clusters involved in electron transfer, and the membrane arm contains 78 transmembrane helices, mostly contributed by antiporter-like subunits involved in proton translocation. Supernumerary subunits form an interlinked, stabilizing shell around the conserved core. Tightly bound lipids (including cardiolipins) further stabilize interactions between the hydrophobic subunits. Subunits with possible regulatory roles contain additional cofactors, NADPH and two phosphopantetheine molecules, revealed to be involved in inter-subunit interactions. We observe two different conformations of the complex, which may be related to the conformationally driven coupling mechanism and to the active/deactive transition of the enzyme. Our structure provides insight into complex I mechanism, assembly, maturation and dysfunction, allowing detailed molecular analysis of disease-causing mutations. The electrochemical proton gradient across the inner mitochondrial membrane required by ATP synthase is maintained by the electron transport chain (ETC) proton-pumping complexes I, III and IV1,2. Complex I (CI) is crucial for the entire process and even mild Correspondence and requests for materials should be addressed to L. S. ( Author Contributions: K.F. purified complex I for grid preparation, prepared cryo-EM grids, acquired and processed EM data, and co-built the models; J.A.L. purified complex I for cross-linking experiments, analysed cross-linking data and co-built the models; G.D. performed cross-linking/mass-spectrometry experiments, K.K. performed model re-building in Rosetta and sequence alignments; G.D. and M.S. analysed cross-linking data; L.A.S. designed and supervised the project, processed and analysed data and wrote the manuscript, with contributions from all authors. The authors declare no competing financial interests.
doi:10.1038/nature19794 pmid:27595392 pmcid:PMC5164932 fatcat:zxpsau2h5vfe5nnj7asudpmkc4

Atomic structures of respiratory complex III2, complex IV, and supercomplex III2-IV from vascular plants

Maria Maldonado, Fei Guo, James A Letts
2021 eLife  
., 2016; Letts et al., 2016; Wu et al., 2016; Zhu et al., 2016; Zickermann et al., 2015; Blaza et al., 2018; Guo et al., 2017; Letts et al., 2019; Agip et al., 2018; Parey et al., 2018) , the high-resolution  ...  Although it was initially hypothesized that supercomplexes would allow for direct substrate channeling between complexes, evidence has mounted against this view (Gu et al., 2016; Letts et al., 2016; Letts  ... 
doi:10.7554/elife.62047 pmid:33463523 pmcid:PMC7815315 fatcat:3toyplzhjbbtnlipdhqyejirxq

Corrigendum to "Genomic and experimental evidence for a potential sexual cycle in the pathogenic thermal dimorphic fungusPenicillium marneffei" [FEBS Lett. 580 (2006) 3409-3416]

Patrick C.Y. Woo, Ken T.K. Chong, Herman Tse, James J. Cai, Candy C.Y. Lau, Anna C. Zhou, Susanna K.P. Lau, Kwok-yung Yuen
2006 FEBS Letters  
doi:10.1016/j.febslet.2006.08.002 fatcat:yz4uxwsfvfdlloa6lkr6wrecxq

A Structural Perspective on the RNA Editing of Plant Respiratory Complexes

Maria Maldonado, Kaitlyn Madison Abe, James Anthony Letts
2022 International Journal of Molecular Sciences  
The last steps of respiration, a core energy-harvesting process, are carried out by a chain of multi-subunit complexes in the inner mitochondrial membrane. Several essential subunits of the respiratory complexes are RNA-edited in plants, frequently leading to changes in the encoded amino acids. While the impact of RNA editing is clear at the sequence and phenotypic levels, the underlying biochemical explanations for these effects have remained obscure. Here, we used the structures of plant
more » ... ratory complex I, complex III2 and complex IV to analyze the impact of the amino acid changes of RNA editing in terms of their location and biochemical features. Through specific examples, we demonstrate how the structural information can explain the phenotypes of RNA-editing mutants. This work shows how the structural perspective can bridge the gap between sequence and phenotype and provides a framework for the continued analysis of RNA-editing mutants in plant mitochondria and, by extension, in chloroplasts.
doi:10.3390/ijms23020684 pmid:35054870 pmcid:PMC8775464 fatcat:r3boc3yeb5ca7hucpm6vazgj4u
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