1
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Marcella AM, Culbertson SJ, Shogren-Knaak MA, Barb AW. Structure, High Affinity, and Negative Cooperativity of the Escherichia coli Holo-(Acyl Carrier Protein):Holo-(Acyl Carrier Protein) Synthase Complex. J Mol Biol 2017; 429:3763-3775. [DOI: 10.1016/j.jmb.2017.10.015] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2017] [Revised: 10/08/2017] [Accepted: 10/11/2017] [Indexed: 01/01/2023]
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2
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Rozentur-Shkop E, Goobes G, Chill JH. A J-modulated protonless NMR experiment characterizes the conformational ensemble of the intrinsically disordered protein WIP. JOURNAL OF BIOMOLECULAR NMR 2016; 66:243-257. [PMID: 27844185 DOI: 10.1007/s10858-016-0073-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/07/2016] [Accepted: 11/01/2016] [Indexed: 06/06/2023]
Abstract
Intrinsically disordered proteins (IDPs) are multi-conformational polypeptides that lack a single stable three-dimensional structure. It has become increasingly clear that the versatile IDPs play key roles in a multitude of biological processes, and, given their flexible nature, NMR is a leading method to investigate IDP behavior on the molecular level. Here we present an IDP-tailored J-modulated experiment designed to monitor changes in the conformational ensemble characteristic of IDPs by accurately measuring backbone one- and two-bond J(15N,13Cα) couplings. This concept was realized using a unidirectional (H)NCO 13C-detected experiment suitable for poor spectral dispersion and optimized for maximum coverage of amino acid types. To demonstrate the utility of this approach we applied it to the disordered actin-binding N-terminal domain of WASp interacting protein (WIP), a ubiquitous key modulator of cytoskeletal changes in a range of biological systems. One- and two-bond J(15N,13Cα) couplings were acquired for WIP residues 2-65 at various temperatures, and in denaturing and crowding environments. Under native conditions fitted J-couplings identified in the WIP conformational ensemble a propensity for extended conformation at residues 16-23 and 45-60, and a helical tendency at residues 28-42. These findings are consistent with a previous study of the based upon chemical shift and RDC data and confirm that the WIP2-65 conformational ensemble is biased towards the structure assumed by this fragment in its actin-bound form. The effects of environmental changes upon this ensemble were readily apparent in the J-coupling data, which reflected a significant decrease in structural propensity at higher temperatures, in the presence of 8 M urea, and under the influence of a bacterial cell lysate. The latter suggests that crowding can cause protein unfolding through protein-protein interactions that stabilize the unfolded state. We conclude that J-couplings are a useful measureable in characterizing structural ensembles in IDPs, and that the proposed experiment provides a practical method for accurately performing such measurements, once again emphasizing the power of NMR in studying IDP behavior.
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Affiliation(s)
| | - Gil Goobes
- Department of Chemistry, Bar Ilan University, 52900, Ramat Gan, Israel
| | - Jordan H Chill
- Department of Chemistry, Bar Ilan University, 52900, Ramat Gan, Israel.
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3
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Zhuo Y, Yang JY, Moremen KW, Prestegard JH. Glycosylation Alters Dimerization Properties of a Cell-surface Signaling Protein, Carcinoembryonic Antigen-related Cell Adhesion Molecule 1 (CEACAM1). J Biol Chem 2016; 291:20085-95. [PMID: 27471271 DOI: 10.1074/jbc.m116.740050] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2016] [Indexed: 12/12/2022] Open
Abstract
Human carcinoembryonic antigen-related cell adhesion molecule 1 (C?/Au: EACAM1) is a cell-surface signaling molecule involved in cell adhesion, proliferation, and immune response. It is also implicated in cancer angiogenesis, progression, and metastasis. This diverse set of effects likely arises as a result of the numerous homophilic and heterophilic interactions that CEACAM1 can have with itself and other molecules. Its N-terminal Ig variable (IgV) domain has been suggested to be a principal player in these interactions. Previous crystal structures of the β-sandwich-like IgV domain have been produced using Escherichia coli-expressed material, which lacks native glycosylation. These have led to distinctly different proposals for dimer interfaces, one involving interactions of ABED β-strands and the other involving GFCC'C″ β-strands, with the former burying one prominent glycosylation site. These structures raise questions as to which form may exist in solution and what the effect of glycosylation may have on this form. Here, we use NMR cross-correlation measurements to examine the effect of glycosylation on CEACAM1-IgV dimerization and use residual dipolar coupling (RDC) measurements to characterize the solution structure of the non-glycosylated form. Our findings demonstrate that even addition of a single N-linked GlcNAc at potential glycosylation sites inhibits dimer formation. Surprisingly, RDC data collected on E. coli expressed material in solution indicate that a dimer using the non-glycosylated GFCC'C″ interface is preferred even in the absence of glycosylation. The results open new questions about what other factors may facilitate dimerization of CEACAM1 in vivo, and what roles glycosylation may play in heterophylic interactions.
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Affiliation(s)
- You Zhuo
- From the Complex Carbohydrate Research Center, University of Georgia, Athens, Georgia 30602
| | - Jeong-Yeh Yang
- From the Complex Carbohydrate Research Center, University of Georgia, Athens, Georgia 30602
| | - Kelley W Moremen
- From the Complex Carbohydrate Research Center, University of Georgia, Athens, Georgia 30602
| | - James H Prestegard
- From the Complex Carbohydrate Research Center, University of Georgia, Athens, Georgia 30602
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4
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Venditti V, Egner TK, Clore GM. Hybrid Approaches to Structural Characterization of Conformational Ensembles of Complex Macromolecular Systems Combining NMR Residual Dipolar Couplings and Solution X-ray Scattering. Chem Rev 2016; 116:6305-22. [PMID: 26739383 PMCID: PMC5590664 DOI: 10.1021/acs.chemrev.5b00592] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Solving structures or structural ensembles of large macromolecular systems in solution poses a challenging problem. While NMR provides structural information at atomic resolution, increased spectral complexity, chemical shift overlap, and short transverse relaxation times (associated with slow tumbling) render application of the usual techniques that have been so successful for medium sized systems (<50 kDa) difficult. Solution X-ray scattering, on the other hand, is not limited by molecular weight but only provides low resolution structural information related to the overall shape and size of the system under investigation. Here we review how combining atomic resolution structures of smaller domains with sparse experimental data afforded by NMR residual dipolar couplings (which yield both orientational and shape information) and solution X-ray scattering data in rigid-body simulated annealing calculations provides a powerful approach for investigating the structural aspects of conformational dynamics in large multidomain proteins. The application of this hybrid methodology is illustrated for the 128 kDa dimer of bacterial Enzyme I which exists in a variety of open and closed states that are sampled at various points in the catalytic cycles, and for the capsid protein of the human immunodeficiency virus.
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Affiliation(s)
- Vincenzo Venditti
- Department of Chemistry, Iowa State University, Ames, Iowa 50011, United States
- Roy J. Carver Department of Biochemistry, Biophysics and Molecular Biology, Iowa State University, Ames, Iowa 50011, United States
| | - Timothy K. Egner
- Department of Chemistry, Iowa State University, Ames, Iowa 50011, United States
| | - G. Marius Clore
- Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892-0520, United States
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5
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Barb AW, Subedi GP. An encodable lanthanide binding tag with reduced size and flexibility for measuring residual dipolar couplings and pseudocontact shifts in large proteins. JOURNAL OF BIOMOLECULAR NMR 2016; 64:75-85. [PMID: 26728077 PMCID: PMC4884023 DOI: 10.1007/s10858-015-0009-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/27/2015] [Accepted: 12/28/2015] [Indexed: 05/03/2023]
Abstract
Metal ions serve important roles in structural biology applications from long-range perturbations seen in magnetic resonance experiments to electron-dense signatures in X-ray crystallography data; however, the metal ion must be secured in a molecular framework to achieve the maximum benefit. Polypeptide-based lanthanide-binding tags (LBTs) represent one option that can be directly encoded within a recombinant protein expression construct. However, LBTs often exhibit significant mobility relative to the target molecule. Here we report the characterization of improved LBTs sequences for insertion into a protein loop. These LBTs were inserted to connect two parallel alpha helices of an immunoglobulin G (IgG)-binding Z domain platform. Variants A and B bound Tb(3+) with high affinity (0.70 and 0.13 μM, respectively) and displayed restricted LBT motion. Compared to the parent construct, the metal-bound A experienced a 2.5-fold reduction in tag motion as measured by magnetic field-induced residual dipolar couplings and was further studied in a 72.2 kDa complex with the human IgG1 fragment crystallizable (IgG1 Fc) glycoprotein. The appearance of both pseudo-contact shifts (-0.221 to 0.081 ppm) and residual dipolar couplings (-7.6 to 14.3 Hz) of IgG1 Fc resonances in the IgG1 Fc:(variant A:Tb(3+))2 complex indicated structural restriction of the LBT with respect to the Fc. These studies highlight the applicability of improved LBT sequences with reduced mobility to probe the structure of macromolecular systems.
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Affiliation(s)
- Adam W Barb
- Roy J. Carver Department of Biochemistry, Biophysics and Molecular Biology, Iowa State University, 2214 Molecular Biology Building, Ames, IA, 50011, USA.
| | - Ganesh P Subedi
- Roy J. Carver Department of Biochemistry, Biophysics and Molecular Biology, Iowa State University, 2214 Molecular Biology Building, Ames, IA, 50011, USA
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6
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Subedi GP, Barb AW. The Structural Role of Antibody N-Glycosylation in Receptor Interactions. Structure 2015; 23:1573-1583. [PMID: 26211613 PMCID: PMC4558368 DOI: 10.1016/j.str.2015.06.015] [Citation(s) in RCA: 135] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2015] [Revised: 06/08/2015] [Accepted: 06/10/2015] [Indexed: 01/06/2023]
Abstract
Asparagine(N)297-linked glycosylation of immunoglobulin G (IgG) Fc is required for binding to FcγRIIa, IIb, and IIIa, although it is unclear how it contributes. We found the quaternary structure of glycosylated Fc was indistinguishable from aglycosylated Fc, indicating that N-glycosylation does not maintain relative Fc Cγ2/Cγ3 domain orientation. However, the conformation of the C'E loop, which contains N297, was significantly perturbed in the aglycosylated Fc variant. The conformation of the C'E loop as measured with a range of Fc variants shows a strong correlation with FcγRIIIa affinity. These results indicate that the primary role of the IgG1 Fc N-glycan is to stabilize the C'E loop through intramolecular interactions between carbohydrate and amino acid residues, and preorganize the FcγRIIIa interface for optimal binding affinity. The features that contribute to the capacity of the IgG1 Fc N-glycan to restrict protein conformation and tune binding affinity are conserved in other antibodies including IgG2-IgG4, IgD, IgE, and IgM.
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Affiliation(s)
- Ganesh P Subedi
- Roy J. Carver Department of Biochemistry, Biophysics and Molecular Biology, Iowa State University, 2214 Molecular Biology Building, Ames, IA 50011, USA
| | - Adam W Barb
- Roy J. Carver Department of Biochemistry, Biophysics and Molecular Biology, Iowa State University, 2214 Molecular Biology Building, Ames, IA 50011, USA.
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7
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Feng W, Wang X. Structure of decorin binding protein B from Borrelia burgdorferi and its interactions with glycosaminoglycans. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2015; 1854:1823-1832. [PMID: 26275806 DOI: 10.1016/j.bbapap.2015.08.003] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/11/2015] [Revised: 07/28/2015] [Accepted: 08/09/2015] [Indexed: 11/26/2022]
Abstract
Decorin-binding proteins (DBPs), DBPA and DBPB, are surface lipoproteins on Borrelia burgdorferi, the causative agent of Lyme disease. DBPs bind to the connective tissue proteoglycan decorin and facilitate tissue colonization by the bacterium. Although structural and biochemical properties of DBPA are well understood, little is known about DBPB. In current work, we determined the solution structure of DBPB from strain B31 of B. burgdorferi and characterized its interactions with glycosaminoglycans (GAGs). Our structure shows that DBPB adopts the same topology as DBPA, but possesses a much shorter terminal helix, resulting in a longer unstructured C-terminal tail, which is also rich in basic amino acids. Characterization of DBPB-GAG interactions reveals that, despite similar GAG affinities of DBPA and DBPB, the primary GAG-binding sites in DBPB are different from DBPA. In particular, our results indicate that lysines in the C-terminus of DBPB are vital to DBPB's ability to bind GAGs whereas C-terminal tail for DBPA from strain B31 only plays a minor role in facilitating GAG bindings. Furthermore, the traditional GAG-binding pocket important to DBPA-GAG interactions is only secondary to DBPB's GAG-binding ability.
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Affiliation(s)
- Wei Feng
- Department of Chemistry & Biochemistry, Arizona State University, Tempe, AZ 85287, USA
| | - Xu Wang
- Department of Chemistry & Biochemistry, Arizona State University, Tempe, AZ 85287, USA.
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8
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Structural mechanisms underlying sequence-dependent variations in GAG affinities of decorin binding protein A, a Borrelia burgdorferi adhesin. Biochem J 2015; 467:439-51. [DOI: 10.1042/bj20141201] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Decorin-binding protein A (DBPA) is an important surface adhesin of the bacterium Borrelia burgdorferi, the causative agent of Lyme disease. DBPA facilitates the bacteria's colonization of human tissue by adhering to glycosaminoglycan (GAG), a sulfated polysaccharide. Interestingly, DBPA sequence variation among different strains of Borrelia spirochetes is high, resulting in significant differences in their GAG affinities. However, the structural mechanisms contributing to these differences are unknown. We determined the solution structures of DBPAs from strain N40 of B. burgdorferi and strain PBr of Borrelia garinii, two DBPA variants whose GAG affinities deviate significantly from strain B31, the best characterized version of DBPA. Our structures revealed that significant differences exist between PBr DBPA and B31/N40 DBPAs. In particular, the C-terminus of PBr DBPA, unlike C-termini from B31 and N40 DBPAs, is positioned away from the GAG-binding pocket and the linker between helices one and two of PBr DBPA is highly structured and retracted from the GAG-binding pocket. The repositioning of the C-terminus allowed the formation of an extra GAG-binding epitope in PBr DBPA and the retracted linker gave GAG ligands more access to the GAG-binding epitopes than other DBPAs. Characterization of GAG ligands' interactions with wild-type (WT) PBr and mutants confirmed the importance of the second major GAG-binding epitope and established the fact that the two epitopes are independent of one another and the new epitope is as important to GAG binding as the traditional epitope.
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9
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Lemak A, Wu B, Yee A, Houliston S, Lee HW, Gutmanas A, Fang X, Garcia M, Semesi A, Wang YX, Prestegard JH, Arrowsmith CH. Structural characterization of a flexible two-domain protein in solution using small angle X-ray scattering and NMR data. Structure 2014; 22:1862-1874. [PMID: 25456817 PMCID: PMC5046226 DOI: 10.1016/j.str.2014.09.013] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2014] [Revised: 09/10/2014] [Accepted: 09/12/2014] [Indexed: 01/09/2023]
Abstract
Multidomain proteins in which individual domains are connected by linkers often possess inherent interdomain flexibility that significantly complicates their structural characterization in solution using either nuclear magnetic resonance (NMR) spectroscopy or small-angle X-ray scattering (SAXS) alone. Here, we report a protocol for joint refinement of flexible multidomain protein structures against NMR distance and angular restraints, residual dipolar couplings, and SAXS data. The protocol is based on the ensemble optimization method principle (Bernadó et al., 2007) and is compared with different refinement strategies for the structural characterization of the flexible two-domain protein sf3636 from Shigella flexneri 2a. The results of our refinement suggest the existence of a dominant population of configurational states in solution possessing an overall elongated shape and restricted relative twisting of the two domains.
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Affiliation(s)
- Alexander Lemak
- Princess Margaret Cancer Centre, Toronto, ON M5G 2M9, Canada; Department of Medical Biophysics, University of Toronto, Toronto, ON M5G 2M9, Canada
| | - Bin Wu
- Princess Margaret Cancer Centre, Toronto, ON M5G 2M9, Canada; Department of Medical Biophysics, University of Toronto, Toronto, ON M5G 2M9, Canada
| | - Adelinda Yee
- Princess Margaret Cancer Centre, Toronto, ON M5G 2M9, Canada; Department of Medical Biophysics, University of Toronto, Toronto, ON M5G 2M9, Canada
| | - Scott Houliston
- Princess Margaret Cancer Centre, Toronto, ON M5G 2M9, Canada; Department of Medical Biophysics, University of Toronto, Toronto, ON M5G 2M9, Canada
| | - Hsiau-Wei Lee
- Complex Carbohydrate Research Center, University of Georgia, Athens, GA 30602, USA
| | - Aleksandras Gutmanas
- Princess Margaret Cancer Centre, Toronto, ON M5G 2M9, Canada; Department of Medical Biophysics, University of Toronto, Toronto, ON M5G 2M9, Canada
| | - Xianyang Fang
- Protein-Nucleic Acid Interaction Section, Structural Biophysics Laboratory, National Cancer Institute at Frederick, National Institutes of Health, Frederick, MD 21702, USA
| | - Maite Garcia
- Princess Margaret Cancer Centre, Toronto, ON M5G 2M9, Canada; Department of Medical Biophysics, University of Toronto, Toronto, ON M5G 2M9, Canada
| | - Anthony Semesi
- Princess Margaret Cancer Centre, Toronto, ON M5G 2M9, Canada; Department of Medical Biophysics, University of Toronto, Toronto, ON M5G 2M9, Canada
| | - Yun-Xing Wang
- Protein-Nucleic Acid Interaction Section, Structural Biophysics Laboratory, National Cancer Institute at Frederick, National Institutes of Health, Frederick, MD 21702, USA
| | - James H Prestegard
- Complex Carbohydrate Research Center, University of Georgia, Athens, GA 30602, USA
| | - Cheryl H Arrowsmith
- Princess Margaret Cancer Centre, Toronto, ON M5G 2M9, Canada; Department of Medical Biophysics, University of Toronto, Toronto, ON M5G 2M9, Canada.
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10
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Pulavarti SVSRK, Huang YJ, Pederson K, Acton TB, Xiao R, Everett JK, Prestegard JH, Montelione GT, Szyperski T. Solution NMR structures of immunoglobulin-like domains 7 and 12 from obscurin-like protein 1 contribute to the structural coverage of the Human Cancer Protein Interaction Network. JOURNAL OF STRUCTURAL AND FUNCTIONAL GENOMICS 2014; 15:209-214. [PMID: 24989974 PMCID: PMC4945113 DOI: 10.1007/s10969-014-9185-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/31/2014] [Accepted: 06/14/2014] [Indexed: 06/03/2023]
Abstract
High-quality solution NMR structures of immunoglobulin-like domains 7 and 12 from human obscurin-like protein 1 were solved. The two domains share 30% sequence identity and their structures are, as expected, rather similar. The new structures contribute to structural coverage of human cancer associated proteins. Mutations of Arg 812 in domain 7 cause the rare 3-M syndrome, and this site is located in a surface area predicted to be involved in protein-protein interactions.
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Affiliation(s)
- Surya VSRK Pulavarti
- Department of Chemistry, The State University of New York at Buffalo, and Northeast Structural Genomics Consortium, Buffalo, NY 14260, USA
| | - Yuanpeng J. Huang
- Center of Advanced Biotechnology and Medicine and Department of Molecular Biology and Biochemistry, Rutgers, The State University of New Jersey and Northeast Structural Genomics Consortium, Piscataway, NJ 08854, USA
| | - Kari Pederson
- Complex Carbohydrate Research Center, University of Georgia, and Northeast Structural Genomics Consortium, Athens, GA 30602, USA
| | - Thomas B. Acton
- Center of Advanced Biotechnology and Medicine and Department of Molecular Biology and Biochemistry, Rutgers, The State University of New Jersey and Northeast Structural Genomics Consortium, Piscataway, NJ 08854, USA
| | - Rong Xiao
- Center of Advanced Biotechnology and Medicine and Department of Molecular Biology and Biochemistry, Rutgers, The State University of New Jersey and Northeast Structural Genomics Consortium, Piscataway, NJ 08854, USA
| | - John K. Everett
- Center of Advanced Biotechnology and Medicine and Department of Molecular Biology and Biochemistry, Rutgers, The State University of New Jersey and Northeast Structural Genomics Consortium, Piscataway, NJ 08854, USA
| | - James H. Prestegard
- Complex Carbohydrate Research Center, University of Georgia, and Northeast Structural Genomics Consortium, Athens, GA 30602, USA
| | - Gaetano T. Montelione
- Center of Advanced Biotechnology and Medicine and Department of Molecular Biology and Biochemistry, Rutgers, The State University of New Jersey and Northeast Structural Genomics Consortium, Piscataway, NJ 08854, USA
| | - Thomas Szyperski
- Department of Chemistry, The State University of New York at Buffalo, and Northeast Structural Genomics Consortium, Buffalo, NY 14260, USA
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11
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Pulavarti SVSRK, Eletsky A, Lee HW, Acton TB, Xiao R, Everett JK, Prestegard JH, Montelione GT, Szyperski T. Solution NMR structure of CD1104B from pathogenic Clostridium difficile reveals a distinct α-helical architecture and provides first structural representative of protein domain family PF14203. JOURNAL OF STRUCTURAL AND FUNCTIONAL GENOMICS 2013; 14:155-160. [PMID: 24048810 PMCID: PMC3844015 DOI: 10.1007/s10969-013-9164-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/03/2013] [Accepted: 09/10/2013] [Indexed: 05/30/2023]
Abstract
A high-quality structure of the 68-residue protein CD1104B from Clostridium difficile strain 630 exhibits a distinct all α-helical fold. The structure presented here is the first representative of bacterial protein domain family PF14203 (currently 180 members) of unknown function (DUF4319) and reveals that the side-chains of the only two strictly conserved residues (Glu 8 and Lys 48) form a salt bridge. Moreover, these two residues are located in the vicinity of the largest surface cleft which is predicted to contribute to a surface area involved in protein-protein interactions. This, along with its coding in transposon CTn4, suggests that CD1104B (and very likely all members of Pfam 14203) functions by interacting with other proteins required for the transfer of transposons between different bacterial species.
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Affiliation(s)
- Surya VSRK Pulavarti
- Department of Chemistry, The State University of New York at Buffalo, and Northeast Structural Genomics Consortium, Buffalo, NY 14260, USA
| | - Alexander Eletsky
- Department of Chemistry, The State University of New York at Buffalo, and Northeast Structural Genomics Consortium, Buffalo, NY 14260, USA
| | - Hsiau-Wei Lee
- Complex Carbohydrate Research Center, University at Georgia, and Northeast Structural Genomics Consortium, Athens, GA 30602, USA
| | - Thomas B. Acton
- Center of Advanced Biotechnology and Medicine and Department of Molecular Biology and Biochemistry, Rutgers, The State University of New Jersey and Northeast Structural Genomics Consortium, Piscataway, NJ 08854, USA
| | - Rong Xiao
- Center of Advanced Biotechnology and Medicine and Department of Molecular Biology and Biochemistry, Rutgers, The State University of New Jersey and Northeast Structural Genomics Consortium, Piscataway, NJ 08854, USA
| | - John K. Everett
- Center of Advanced Biotechnology and Medicine and Department of Molecular Biology and Biochemistry, Rutgers, The State University of New Jersey and Northeast Structural Genomics Consortium, Piscataway, NJ 08854, USA
| | - James H. Prestegard
- Complex Carbohydrate Research Center, University at Georgia, and Northeast Structural Genomics Consortium, Athens, GA 30602, USA
| | - Gaetano T. Montelione
- Center of Advanced Biotechnology and Medicine and Department of Molecular Biology and Biochemistry, Rutgers, The State University of New Jersey and Northeast Structural Genomics Consortium, Piscataway, NJ 08854, USA, Department of Biochemistry and Molecular Biology, Robert Wood Johnson Medical School, UMDNJ, Piscataway NJ 08854, USA
| | - Thomas Szyperski
- Department of Chemistry, The State University of New York at Buffalo, and Northeast Structural Genomics Consortium, Buffalo, NY 14260, USA
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12
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Frueh DP, Goodrich AC, Mishra SH, Nichols SR. NMR methods for structural studies of large monomeric and multimeric proteins. Curr Opin Struct Biol 2013; 23:734-9. [PMID: 23850141 PMCID: PMC3805735 DOI: 10.1016/j.sbi.2013.06.016] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2013] [Revised: 06/13/2013] [Accepted: 06/21/2013] [Indexed: 12/16/2022]
Abstract
NMR structural studies of large monomeric and multimeric proteins face distinct challenges. In large monomeric proteins, the common occurrence of frequency degeneracies between residues impedes unambiguous assignment of NMR signals. To overcome this barrier, nonuniform sampling (NUS) is used to measure spectra with optimal resolution within reasonable time, new correlation maps resolve previous impasses in assignment strategies, and novel selective methyl labeling schemes provide additional structural probes without cluttering NMR spectra. These advances push the limits of NMR studies of large monomeric proteins. Large multimeric and multidomain proteins are studied by NMR when individual components can also be studied by NMR and have known structures. The structural properties of large assemblies are obtained by identifying binding surfaces, by orienting domains, and employing limited distance constraints. Segmental labeling and the combination of NMR with other methods have helped popularize NMR studies of such systems.
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Affiliation(s)
- Dominique P Frueh
- Department of Biophysics and Biophysical Chemistry, Johns Hopkins School of Medicine, Baltimore, MD 21205, USA.
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13
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Dürr UN, Gildenberg M, Ramamoorthy A. The magic of bicelles lights up membrane protein structure. Chem Rev 2012; 112:6054-74. [PMID: 22920148 PMCID: PMC3497859 DOI: 10.1021/cr300061w] [Citation(s) in RCA: 266] [Impact Index Per Article: 22.2] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2012] [Indexed: 12/12/2022]
Affiliation(s)
| | - Melissa Gildenberg
- Biophysics
and Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109-1055,
United States
| | - Ayyalusamy Ramamoorthy
- Biophysics
and Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109-1055,
United States
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14
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Wang X. Solution structure of decorin-binding protein A from Borrelia burgdorferi. Biochemistry 2012; 51:8353-62. [PMID: 22985470 DOI: 10.1021/bi3007093] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Decorin-binding protein A (DBPA) is an important lipoprotein from the bacterium Borrelia burgdorferi, the causative agent of Lyme disease. The absence of DBPA drastically reduces the pathogenic potential of the bacterium, and biochemical evidence indicates DBPA's interactions with the glycosaminoglycan (GAG) portion of decorin are crucial to its function. We have determined the solution structure of DBPA and studied DBPA's interactions with various forms of GAGs. DBPA is determined to be a helical bundle protein consisting of five helices held together by a strong hydrophobic core. The structure also possesses a basic patch formed by portions of two helices and two flexible linkers. Low-molecular mass heparin-induced chemical shift perturbations for residues in the region as well as increases in signal intensities of select residues in their presence confirm residues in the pocket are perturbed by heparin binding. Dermatan sulfate fragments, the dominant GAG type found on decorin, were shown to have lower affinity than heparin but are still capable of binding DBPA.
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Affiliation(s)
- Xu Wang
- Department of Chemistry and Biochemistry, Arizona State University, Tempe, AZ 85287, USA.
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15
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Barb AW, Ho TG, Flanagan-Steet H, Prestegard JH. Lanthanide binding and IgG affinity construct: potential applications in solution NMR, MRI, and luminescence microscopy. Protein Sci 2012; 21:1456-66. [PMID: 22851279 DOI: 10.1002/pro.2133] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2012] [Revised: 07/16/2012] [Accepted: 07/17/2012] [Indexed: 11/06/2022]
Abstract
Paramagnetic lanthanide ions when bound to proteins offer great potential for structural investigations that utilize solution nuclear magnetic resonance spectroscopy, magnetic resonance imaging, or optical microscopy. However, many proteins do not have native metal ion binding sites and engineering a chimeric protein to bind an ion while retaining affinity for a protein of interest represents a significant challenge. Here we report the characterization of an immunoglobulin G-binding protein redesigned to include a lanthanide binding motif in place of a loop between two helices (Z-L2LBT). It was shown to bind Tb³⁺ with 130 nM affinity. Ions such as Dy³⁺, Yb³⁺, and Ce³⁺ produce paramagnetic effects on NMR spectra and the utility of these effects is illustrated by their use in determining a structural model of the metal-complexed Z-L2LBT protein and a preliminary characterization of the dynamic distribution of IgG Fc glycan positions. Furthermore, this designed protein is demonstrated to be a novel IgG-binding reagent for magnetic resonance imaging (Z-L2LBT:Gd³⁺ complex) and luminescence microscopy (Z-L2LBT: Tb³⁺ complex).
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Affiliation(s)
- Adam W Barb
- Complex Carbohydrate Research Center, The University of Georgia, Athens, Georgia, USA
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16
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Koehler J, Meiler J. Expanding the utility of NMR restraints with paramagnetic compounds: background and practical aspects. PROGRESS IN NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY 2011; 59:360-89. [PMID: 22027343 PMCID: PMC3202700 DOI: 10.1016/j.pnmrs.2011.05.001] [Citation(s) in RCA: 103] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/20/2011] [Accepted: 05/06/2011] [Indexed: 05/05/2023]
Affiliation(s)
- Julia Koehler
- Department of Chemistry, Center for Structural Biology, Vanderbilt University, Nashville, TN 37232-8725, USA.
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17
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Löhr F, Reckel S, Stefer S, Dötsch V, Schmidt JM. Improved accuracy in measuring one-bond and two-bond (15)N, (13)C (α) coupling constants in proteins by double-inphase/antiphase (DIPAP) spectroscopy. JOURNAL OF BIOMOLECULAR NMR 2011; 50:167-190. [PMID: 21647741 DOI: 10.1007/s10858-011-9507-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2011] [Accepted: 04/25/2011] [Indexed: 05/30/2023]
Abstract
An extension to HN(CO-α/β-N,C(α)-J)-TROSY (Permi and Annila in J Biomol NMR 16:221-227, 2000) is proposed that permits the simultaneous determination of the four coupling constants (1) J (N'(i)Cα(i)), (2) J (HN(i)Cα(i)), (2) J (Cα(i-1)N'(i)), and (3) J (Cα(i-1)HN(i)) in (15)N,(13)C-labeled proteins. Contrasting the original scheme, in which two separate subspectra exhibit the (2) J (CαN') coupling as inphase and antiphase splitting (IPAP), we here record four subspectra that exhibit all combinations of inphase and antiphase splittings possible with respect to both (2) J (CαN') and (1) J (N'Cα) (DIPAP). Complementary sign patterns in the different spectrum constituents overdetermine the coupling constants which can thus be extracted at higher accuracy than is possible with the original experiment. Fully exploiting data redundance, simultaneous 2D lineshape fitting of the E.COSY multiplet tilts in all four subspectra provides all coupling constants at ultimate precision. Cross-correlation and differential-relaxation effects were taken into account in the evaluation procedure. By applying a four-point Fourier transform, the set of spectra is reversibly interconverted between DIPAP and spin-state representations. Methods are exemplified using proteins of various size.
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Affiliation(s)
- Frank Löhr
- Institute of Biophysical Chemistry, Center for Biomolecular Magnetic Resonance, Goethe-University, Frankfurt am Main, Germany.
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18
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Barb AW, Cort JR, Seetharaman J, Lew S, Lee HW, Acton T, Xiao R, Kennedy MA, Tong L, Montelione GT, Prestegard JH. Structures of domains I and IV from YbbR are representative of a widely distributed protein family. Protein Sci 2011; 20:396-405. [PMID: 21154411 DOI: 10.1002/pro.571] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2010] [Revised: 11/19/2010] [Accepted: 11/19/2010] [Indexed: 01/27/2023]
Abstract
YbbR domains are widespread throughout Eubacteria and are expressed as monomeric units, linked in tandem repeats or cotranslated with other domains. Although the precise role of these domains remains undefined, the location of the multiple YbbR domain-encoding ybbR gene in the Bacillus subtilis glmM operon and its previous identification as a substrate for a surfactin-type phosphopantetheinyl transferase suggests a role in cell growth, division, and virulence. To further characterize the YbbR domains, structures of two of the four domains (I and IV) from the YbbR-like protein of Desulfitobacterium hafniense Y51 were solved by solution nuclear magnetic resonance and X-ray crystallography. The structures show the domains to have nearly identical topologies despite a low amino acid identity (23%). The topology is dominated by β-strands, roughly following a "figure 8" pattern with some strands coiling around the domain perimeter and others crossing the center. A similar topology is found in the C-terminal domain of two stress-responsive bacterial ribosomal proteins, TL5 and L25. Based on these models, a structurally guided amino acid alignment identifies features of the YbbR domains that are not evident from naïve amino acid sequence alignments. A structurally conserved cis-proline (cis-Pro) residue was identified in both domains, though the local structure in the immediate vicinities surrounding this residue differed between the two models. The conservation and location of this cis-Pro, plus anchoring Val residues, suggest this motif may be significant to protein function.
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Affiliation(s)
- Adam W Barb
- Complex Carbohydrate Research Center, The University of Georgia, Athens, Georgia, USA
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19
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Huang Y, Zhou Y, Wong HC, Castiblanco A, Chen Y, Brown EM, Yang JJ. Calmodulin regulates Ca2+-sensing receptor-mediated Ca2+ signaling and its cell surface expression. J Biol Chem 2010; 285:35919-31. [PMID: 20826781 DOI: 10.1074/jbc.m110.147918] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
The Ca(2+)-sensing receptor (CaSR) is a member of family C of the GPCRs responsible for sensing extracellular Ca(2+) ([Ca(2+)](o)) levels, maintaining extracellular Ca(2+) homeostasis, and transducing Ca(2+) signaling from the extracellular milieu to the intracellular environment. In the present study, we have demonstrated a Ca(2+)-dependent, stoichiometric interaction between CaM and a CaM-binding domain (CaMBD) located within the C terminus of CaSR (residues 871-898). Our studies suggest a wrapping around 1-14-like mode of interaction that involves global conformational changes in both lobes of CaM with concomitant formation of a helical structure in the CaMBD. More importantly, the Ca(2+)-dependent association between CaM and the C terminus of CaSR is critical for maintaining proper responsiveness of intracellular Ca(2+) responses to changes in extracellular Ca(2+) and regulating cell surface expression of the receptor.
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Affiliation(s)
- Yun Huang
- Department of Chemistry, Center for Drug Design and Advanced Biotechnology, Georgia State University, Atlanta, Georgia 30303, USA
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20
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Liu Y, Prestegard JH. A device for the measurement of residual chemical shift anisotropy and residual dipolar coupling in soluble and membrane-associated proteins. JOURNAL OF BIOMOLECULAR NMR 2010; 47:249-58. [PMID: 20506033 PMCID: PMC2941885 DOI: 10.1007/s10858-010-9427-7] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/22/2010] [Accepted: 05/12/2010] [Indexed: 05/13/2023]
Abstract
Residual dipolar coupling (RDC) and residual chemical shift anisotropy (RCSA) report on orientational properties of a dipolar bond vector and a chemical shift anisotropy principal axis system, respectively. They can be highly complementary in the analysis of backbone structure and dynamics in proteins as RCSAs generally include a report on vectors out of a peptide plane while RDCs usually report on in-plane vectors. Both RDC and RCSA average to zero in isotropic solutions and require partial orientation in a magnetic field to become observable. While the alignment and measurement of RDC has become routine, that of RCSA is less common. This is partly due to difficulties in providing a suitable isotopic reference spectrum for the measurement of the small chemical shift offsets coming from RCSA. Here we introduce a device (modified NMR tube) specifically designed for accurate measurement of reference and aligned spectra for RCSA measurements, but with a capacity for RDC measurements as well. Applications to both soluble and membrane anchored proteins are illustrated.
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21
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Liu Y, Kahn RA, Prestegard JH. Dynamic structure of membrane-anchored Arf*GTP. Nat Struct Mol Biol 2010; 17:876-81. [PMID: 20601958 PMCID: PMC2921649 DOI: 10.1038/nsmb.1853] [Citation(s) in RCA: 111] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2010] [Accepted: 04/13/2010] [Indexed: 11/11/2022]
Abstract
Arfs (ADP ribosylation factors) are N-myristoylated GTP/GDP switch proteins playing key regulatory roles in vesicle transport in eukaryotic cells. ARFs execute their roles by anchoring to membrane surfaces where they interact with other proteins to initiate budding and maturation of transport vesicles. However, existing structures of Arf•GTP are limited to non-myristoylated and truncated forms with impaired membrane binding. We report a high resolution NMR structure for full-length myristoylated yeast (Saccharomyces cerevisiae) Arf1 in complex with a membrane mimic. The two domain structure, in which the myristoylated N-terminal helix is separated from the C-terminal domain by a flexible linker, suggests a level of adaptability in binding modes for the myriad of proteins with which Arf interacts, and allows predictions of specific lipid binding sites on some of these proteins.
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Affiliation(s)
- Yizhou Liu
- Complex Carbohydrate Research Center, University of Georgia, Athens, Georgia, USA
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22
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Schmidt JM, Hua Y, Löhr F. Correlation of (2)J couplings with protein secondary structure. Proteins 2010; 78:1544-62. [PMID: 20131375 DOI: 10.1002/prot.22672] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Geminal two-bond couplings ((2)J) in proteins were analyzed in terms of correlation with protein secondary structure. NMR coupling constants measured and evaluated for a total six proteins comprise 3999 values of (2)J(CalphaN'), (2)J(C'HN), (2)J(HNCalpha), (2)J(C'Calpha), (2)J(HalphaC'), (2)J(HalphaCalpha), (2)J(CbetaC'), (2)J(N'Halpha), (2)J(N'Cbeta), and (2)J(N'C'), encompassing an aggregate 969 amino-acid residues. A seamless chain of pattern comparisons across the spectrum datasets recorded allowed the absolute signs of all (2)J coupling constants studied to be retrieved. Grouped by their mediating nucleus, C', N' or C(alpha), (2)J couplings related to C' and N' depend significantly on phi,psi torsion-angle combinations. beta turn types I, I', II and II', especially, can be distinguished on the basis of relative-value patterns of (2)J(CalphaN'), (2)J(HNCalpha), (2)J(C'HN), and (2)J(HalphaC'). These coupling types also depend on planar or tetrahedral bond angles, whereas such dependences seem insignificant for other types. (2)J(HalphaCbeta) appears to depend on amino-acid type only, showing negligible correlation with torsion-angle geometry. Owing to its unusual properties, (2)J(CalphaN') can be considered a "one-bond" rather than two-bond interaction, the allylic analog of (1)J(N'Calpha), as it were. Of all protein J coupling types, (2)J(CalphaN') exhibits the strongest dependence on molecular conformation, and among the (2)J types, (2)J(HNCalpha) comes second in terms of significance, yet was hitherto barely attended to in protein structure work.
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Affiliation(s)
- Jürgen M Schmidt
- Department of Biosciences, University of Kent, Canterbury, United Kingdom.
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