Other search tools

About this data

The publication data currently available has been vetted by Vanderbilt faculty, staff, administrators and trainees. The data itself is retrieved directly from NCBI's PubMed and is automatically updated on a weekly basis to ensure accuracy and completeness.

If you have any questions or comments, please contact us.

Results: 1 to 10 of 452

Publication Record

Connections

The Structure of the Bifunctional Everninomicin Biosynthetic Enzyme EvdMO1 Suggests Independent Activity of the Fused Methyltransferase-Oxidase Domains.
Starbird CA, Perry NA, Chen Q, Berndt S, Yamakawa I, Loukachevitch LV, Limbrick EM, Bachmann BO, Iverson TM, McCulloch KM
(2018) Biochemistry 57: 6827-6837
MeSH Terms: Amino Acid Sequence, Aminoglycosides, Bacterial Proteins, Biosynthetic Pathways, Catalytic Domain, Conserved Sequence, Crystallography, X-Ray, Gene Fusion, Genes, Bacterial, Methyltransferases, Micromonospora, Models, Molecular, Oxygenases, Protein Interaction Domains and Motifs, Sequence Homology, Amino Acid
Show Abstract · Added April 1, 2019
Members of the orthosomycin family of natural products are decorated polysaccharides with potent antibiotic activity and complex biosynthetic pathways. The defining feature of the orthosomycins is an orthoester linkage between carbohydrate moieties that is necessary for antibiotic activity and is likely formed by a family of conserved oxygenases. Everninomicins are octasaccharide orthosomycins produced by Micromonospora carbonacea that have two orthoester linkages and a methylenedioxy bridge, three features whose formation logically requires oxidative chemistry. Correspondingly, the evd gene cluster encoding everninomicin D encodes two monofunctional nonheme iron, α-ketoglutarate-dependent oxygenases and one bifunctional enzyme with an N-terminal methyltransferase domain and a C-terminal oxygenase domain. To investigate whether the activities of these domains are linked in the bifunctional enzyme EvdMO1, we determined the structure of the N-terminal methyltransferase domain to 1.1 Å and that of the full-length protein to 3.35 Å resolution. Both domains of EvdMO1 adopt the canonical folds of their respective superfamilies and are connected by a short linker. Each domain's active site is oriented such that it faces away from the other domain, and there is no evidence of a channel connecting the two. Our results support EvdMO1 working as a bifunctional enzyme with independent catalytic activities.
0 Communities
1 Members
0 Resources
15 MeSH Terms
Dynamic Glycosylation Governs the Vertebrate COPII Protein Trafficking Pathway.
Cox NJ, Unlu G, Bisnett BJ, Meister TR, Condon BM, Luo PM, Smith TJ, Hanna M, Chhetri A, Soderblom EJ, Audhya A, Knapik EW, Boyce M
(2018) Biochemistry 57: 91-107
MeSH Terms: Acetylglucosamine, Acylation, Animals, COP-Coated Vesicles, Cell Line, Collagen, Craniofacial Abnormalities, Disease Models, Animal, Glycosylation, Humans, Organelles, Protein Conformation, Protein Processing, Post-Translational, Protein Transport, Vertebrates, Vesicular Transport Proteins, Zebrafish
Show Abstract · Added March 15, 2018
The COPII coat complex, which mediates secretory cargo trafficking from the endoplasmic reticulum, is a key control point for subcellular protein targeting. Because misdirected proteins cannot function, protein sorting by COPII is critical for establishing and maintaining normal cell and tissue homeostasis. Indeed, mutations in COPII genes cause a range of human pathologies, including cranio-lenticulo-sutural dysplasia (CLSD), which is characterized by collagen trafficking defects, craniofacial abnormalities, and skeletal dysmorphology. Detailed knowledge of the COPII pathway is required to understand its role in normal cell physiology and to devise new treatments for disorders in which it is disrupted. However, little is known about how vertebrates dynamically regulate COPII activity in response to developmental, metabolic, or pathological cues. Several COPII proteins are modified by O-linked β-N-acetylglucosamine (O-GlcNAc), a dynamic form of intracellular protein glycosylation, but the biochemical and functional effects of these modifications remain unclear. Here, we use a combination of chemical, biochemical, cellular, and genetic approaches to demonstrate that site-specific O-GlcNAcylation of COPII proteins mediates their protein-protein interactions and modulates cargo secretion. In particular, we show that individual O-GlcNAcylation sites of SEC23A, an essential COPII component, are required for its function in human cells and vertebrate development, because mutation of these sites impairs SEC23A-dependent in vivo collagen trafficking and skeletogenesis in a zebrafish model of CLSD. Our results indicate that O-GlcNAc is a conserved and critical regulatory modification in the vertebrate COPII-dependent trafficking pathway.
0 Communities
1 Members
0 Resources
17 MeSH Terms
Dodecyl-β-melibioside Detergent Micelles as a Medium for Membrane Proteins.
Hutchison JM, Lu Z, Li GC, Travis B, Mittal R, Deatherage CL, Sanders CR
(2017) Biochemistry 56: 5481-5484
MeSH Terms: Amyloid beta-Protein Precursor, Detergents, Diacylglycerol Kinase, Disaccharides, Dynamic Light Scattering, Enzyme Stability, Escherichia coli Proteins, Glucosides, Glycolipids, Hot Temperature, Humans, Micelles, Myelin Proteins, Nuclear Magnetic Resonance, Biomolecular, Particle Size, Peptide Fragments, Protein Interaction Domains and Motifs, Protein Stability, Receptor, Notch1
Show Abstract · Added November 21, 2018
There remains a need for new non-ionic detergents that are suitable for use in biochemical and biophysical studies of membrane proteins. Here we explore the properties of n-dodecyl-β-melibioside (β-DDMB) micelles as a medium for membrane proteins. Melibiose is d-galactose-α(1→6)-d-glucose. Light scattering showed the β-DDMB micelle to be roughly 30 kDa smaller than micelles formed by the commonly used n-dodecyl-β-maltoside (β-DDM). β-DDMB stabilized diacylglycerol kinase (DAGK) against thermal inactivation. Moreover, activity assays conducted using aliquots of DAGK purified into β-DDMB yielded activities that were 40% higher than those of DAGK purified into β-DDM. β-DDMB yielded similar or better TROSY-HSQC NMR spectra for two single-pass membrane proteins and the tetraspan membrane protein peripheral myelin protein 22. β-DDMB appears be a useful addition to the toolbox of non-ionic detergents available for membrane protein research.
0 Communities
1 Members
0 Resources
MeSH Terms
Horse Liver Alcohol Dehydrogenase: Zinc Coordination and Catalysis.
Plapp BV, Savarimuthu BR, Ferraro DJ, Rubach JK, Brown EN, Ramaswamy S
(2017) Biochemistry 56: 3632-3646
MeSH Terms: 2,2'-Dipyridyl, Adenosine Diphosphate Ribose, Alcohol Dehydrogenase, Animals, Catalytic Domain, Crystallography, X-Ray, Formamides, Horses, Kinetics, Liver, Models, Molecular, NAD, Phenanthrolines, Protein Binding, Protein Conformation, Water, Zinc
Show Abstract · Added August 31, 2017
During catalysis by liver alcohol dehydrogenase (ADH), a water bound to the catalytic zinc is replaced by the oxygen of the substrates. The mechanism might involve a pentacoordinated zinc or a double-displacement reaction with participation by a nearby glutamate residue, as suggested by studies of human ADH3, yeast ADH1, and some other tetrameric ADHs. Zinc coordination and participation of water in the enzyme mechanism were investigated by X-ray crystallography. The apoenzyme and its complex with adenosine 5'-diphosphoribose have an open protein conformation with the catalytic zinc in one position, tetracoordinated by Cys-46, His-67, Cys-174, and a water molecule. The bidentate chelators 2,2'-bipyridine and 1,10-phenanthroline displace the water and form a pentacoordinated zinc. The enzyme-NADH complex has a closed conformation similar to that of ternary complexes with coenzyme and substrate analogues; the coordination of the catalytic zinc is similar to that found in the apoenzyme, except that a minor, alternative position for the catalytic zinc is ∼1.3 Å from the major position and closer to Glu-68, which could form the alternative coordination to the catalytic zinc. Complexes with NADH and N-1-methylhexylformamide or N-benzylformamide (or with NAD and fluoro alcohols) have the classical tetracoordinated zinc, and no water is bound to the zinc or the nicotinamide rings. The major forms of the enzyme in the mechanism have a tetracoordinated zinc, where the carboxylate group of Glu-68 could participate in the exchange of water and substrates on the zinc. Hydride transfer in the Michaelis complexes does not involve a nearby water.
0 Communities
1 Members
0 Resources
17 MeSH Terms
Structures of the Streptococcus sanguinis SrpA Binding Region with Human Sialoglycans Suggest Features of the Physiological Ligand.
Loukachevitch LV, Bensing BA, Yu H, Zeng J, Chen X, Sullam PM, Iverson TM
(2016) Biochemistry 55: 5927-5937
Show Abstract · Added April 1, 2019
Streptococcus sanguinis is a leading cause of bacterial infective endocarditis, a life-threatening infection of heart valves. S. sanguinis binds to human platelets with high avidity, and this adherence is likely to enhance virulence. Previous studies suggest that a serine-rich repeat adhesin termed SrpA mediates the binding of S. sanguinis to human platelets via its interaction with sialoglycans on the receptor GPIbα. However, in vitro binding assays with SrpA and defined sialoglycans failed to identify specific high-affinity ligands. To improve our understanding of the interaction between SrpA and human platelets, we determined cocrystal structures of the SrpA sialoglycan binding region (SrpA) with five low-affinity ligands: three sialylated trisaccharides (sialyl-T antigen, 3'-sialyllactose, and 3'-sialyl-N-acetyllactosamine), a sialylated tetrasaccharide (sialyl-Lewis), and a sialyl galactose disaccharide component common to these sialoglyans. We then combined structural analysis with mutagenesis to further determine whether our observed interactions between SrpA and glycans are important for binding to platelets and to better map the binding site for the physiological receptor. We found that the sialoglycan binding site of SrpA is significantly larger than the sialoglycans cocrystallized in this study, which suggests that binding of SrpA to platelets either is multivalent or occurs via a larger, disialylated glycan.
0 Communities
1 Members
0 Resources
0 MeSH Terms
Documentation of an Imperative To Improve Methods for Predicting Membrane Protein Stability.
Kroncke BM, Duran AM, Mendenhall JL, Meiler J, Blume JD, Sanders CR
(2016) Biochemistry 55: 5002-9
MeSH Terms: Membrane Proteins, Point Mutation, Protein Stability, Thermodynamics
Show Abstract · Added April 7, 2017
There is a compelling and growing need to accurately predict the impact of amino acid mutations on protein stability for problems in personalized medicine and other applications. Here the ability of 10 computational tools to accurately predict mutation-induced perturbation of folding stability (ΔΔG) for membrane proteins of known structure was assessed. All methods for predicting ΔΔG values performed significantly worse when applied to membrane proteins than when applied to soluble proteins, yielding estimated concordance, Pearson, and Spearman correlation coefficients of <0.4 for membrane proteins. Rosetta and PROVEAN showed a modest ability to classify mutations as destabilizing (ΔΔG < -0.5 kcal/mol), with a 7 in 10 chance of correctly discriminating a randomly chosen destabilizing variant from a randomly chosen stabilizing variant. However, even this performance is significantly worse than for soluble proteins. This study highlights the need for further development of reliable and reproducible methods for predicting thermodynamic folding stability in membrane proteins.
1 Communities
3 Members
0 Resources
4 MeSH Terms
Protocols for Molecular Modeling with Rosetta3 and RosettaScripts.
Bender BJ, Cisneros A, Duran AM, Finn JA, Fu D, Lokits AD, Mueller BK, Sangha AK, Sauer MF, Sevy AM, Sliwoski G, Sheehan JH, DiMaio F, Meiler J, Moretti R
(2016) Biochemistry 55: 4748-63
MeSH Terms: Algorithms, Computational Biology, Internet, Models, Molecular, Protein Binding, Protein Conformation, Protein Folding, Protein Interaction Mapping, Proteins, RNA, Software, User-Computer Interface
Show Abstract · Added April 8, 2017
Previously, we published an article providing an overview of the Rosetta suite of biomacromolecular modeling software and a series of step-by-step tutorials [Kaufmann, K. W., et al. (2010) Biochemistry 49, 2987-2998]. The overwhelming positive response to this publication we received motivates us to here share the next iteration of these tutorials that feature de novo folding, comparative modeling, loop construction, protein docking, small molecule docking, and protein design. This updated and expanded set of tutorials is needed, as since 2010 Rosetta has been fully redesigned into an object-oriented protein modeling program Rosetta3. Notable improvements include a substantially improved energy function, an XML-like language termed "RosettaScripts" for flexibly specifying modeling task, new analysis tools, the addition of the TopologyBroker to control conformational sampling, and support for multiple templates in comparative modeling. Rosetta's ability to model systems with symmetric proteins, membrane proteins, noncanonical amino acids, and RNA has also been greatly expanded and improved.
1 Communities
2 Members
0 Resources
12 MeSH Terms
Topologically Diverse Human Membrane Proteins Partition to Liquid-Disordered Domains in Phase-Separated Lipid Vesicles.
Schlebach JP, Barrett PJ, Day CA, Kim JH, Kenworthy AK, Sanders CR
(2016) Biochemistry 55: 985-8
MeSH Terms: Amyloid beta-Protein Precursor, Caveolin 3, Cholesterol, Fluorescent Dyes, Humans, Hydrophobic and Hydrophilic Interactions, Membrane Microdomains, Microscopy, Confocal, Microscopy, Fluorescence, Models, Molecular, Myelin Proteins, Peptide Fragments, Phosphatidylcholines, Phosphatidylethanolamines, Protein Conformation, Protein Interaction Domains and Motifs, Recombinant Proteins, Rhodamines, Sphingomyelins, Unilamellar Liposomes
Show Abstract · Added February 12, 2016
The integration of membrane proteins into "lipid raft" membrane domains influences many biochemical processes. The intrinsic structural properties of membrane proteins are thought to mediate their partitioning between membrane domains. However, whether membrane topology influences the targeting of proteins to rafts remains unclear. To address this question, we examined the domain preference of three putative raft-associated membrane proteins with widely different topologies: human caveolin-3, C99 (the 99 residue C-terminal domain of the amyloid precursor protein), and peripheral myelin protein 22. We find that each of these proteins are excluded from the ordered domains of giant unilamellar vesicles containing coexisting liquid-ordered and liquid-disordered phases. Thus, the intrinsic structural properties of these three topologically distinct disease-linked proteins are insufficient to confer affinity for synthetic raft-like domains.
0 Communities
2 Members
0 Resources
20 MeSH Terms
Conservative Secondary Shell Substitution In Cyclooxygenase-2 Reduces Inhibition by Indomethacin Amides and Esters via Altered Enzyme Dynamics.
Konkle ME, Blobaum AL, Moth CW, Prusakiewicz JJ, Xu S, Ghebreselasie K, Akingbade D, Jacobs AT, Rouzer CA, Lybrand TP, Marnett LJ
(2016) Biochemistry 55: 348-59
MeSH Terms: Amides, Computational Biology, Cyclooxygenase 2, Enzyme Activation, Esters, Indomethacin, Protein Structure, Secondary, Structure-Activity Relationship
Show Abstract · Added February 22, 2016
The cyclooxygenase enzymes (COX-1 and COX-2) are the therapeutic targets of nonsteroidal anti-inflammatory drugs (NSAIDs). Neutralization of the carboxylic acid moiety of the NSAID indomethacin to an ester or amide functionality confers COX-2 selectivity, but the molecular basis for this selectivity has not been completely revealed through mutagenesis studies and/or X-ray crystallographic attempts. We expressed and assayed a number of divergent secondary shell COX-2 active site mutants and found that a COX-2 to COX-1 change at position 472 (Leu in COX-2, Met in COX-1) reduced the potency of enzyme inhibition by a series of COX-2-selective indomethacin amides and esters. In contrast, the potencies of indomethacin, arylacetic acid, propionic acid, and COX-2-selective diarylheterocycle inhibitors were either unaffected or only mildly affected by this mutation. Molecular dynamics simulations revealed identical equilibrium enzyme structures around residue 472; however, calculations indicated that the L472M mutation impacted local low-frequency dynamical COX constriction site motions by stabilizing the active site entrance and slowing constriction site dynamics. Kinetic analysis of inhibitor binding is consistent with the computational findings.
0 Communities
2 Members
0 Resources
8 MeSH Terms
Backbone Flexibility Influences Nucleotide Incorporation by Human Translesion DNA Polymerase η opposite Intrastrand Cross-Linked DNA.
O'Flaherty DK, Guengerich FP, Egli M, Wilds CJ
(2015) Biochemistry 54: 7449-56
MeSH Terms: Chromatography, Liquid, DNA, DNA Damage, DNA-Directed DNA Polymerase, Humans, Kinetics, Tandem Mass Spectrometry
Show Abstract · Added March 14, 2018
Intrastrand cross-links (IaCL) connecting two purine nucleobases in DNA pose a challenge to high-fidelity replication in the cell. Various repair pathways or polymerase bypass can cope with these lesions. The influence of the phosphodiester linkage between two neighboring 2'-deoxyguanosine (dG) residues attached through the O(6) atoms by an alkylene linker on bypass with human DNA polymerase η (hPol η) was explored in vitro. Steady-state kinetics and mass spectrometric analysis of products from nucleotide incorporation revealed that although hPol η is capable of bypassing the 3'-dG in a mostly error-free fashion, significant misinsertion was observed for the 5'-dG of the IaCL containing a butylene or heptylene linker. The lack of the phosphodiester linkage triggered an important increase in frameshift adduct formation across the 5'-dG by hPol η, in comparison to the 5'-dG of IaCL DNA containing the phosphodiester group.
0 Communities
1 Members
0 Resources
7 MeSH Terms