Abstract:
:The central importance of chorismate enzymes in bacteria, fungi, parasites, and plants combined with their absence in mammals makes them attractive targets for antimicrobials and herbicides. Two of these enzymes, anthranilate synthase (AS) and aminodeoxychorismate synthase (ADCS), are structurally and mechanistically similar. The first catalytic step, amination at C2, is common between them, but AS additionally catalyzes pyruvate elimination, aromatizing the aminated intermediate to anthranilate. Despite prior attempts, the conversion of a pyruvate elimination-deficient enzyme into an elimination-proficient one has not been reported. Janus, a bioinformatics method for predicting mutations required to functionally interconvert homologous enzymes, was employed to predict mutations to convert ADCS into AS. A genetic selection on a library of Janus-predicted mutations was performed. Complementation of an AS-deficient strain of Escherichia coli grown on minimal medium led to several ADCS mutants that allow growth in 6 days compared to 2 days for wild-type AS. The purified mutant enzymes catalyze the conversion of chorismate to anthranilate at rates that are ∼50% of the rate of wild-type ADCS-catalyzed conversion of chorismate to aminodeoxychorismate. The residues mutated do not contact the substrate. Molecular dynamics studies suggest that pyruvate elimination is controlled by the conformation of the C2-aminated intermediate. Enzymes that catalyze elimination favor the equatorial conformation, which presents the C2-H to a conserved active site lysine (Lys424) for deprotonation and maximizes stereoelectronic activation. Acid/base catalysis of pyruvate elimination was confirmed in AS and salicylate synthase by showing incorporation of a solvent-derived proton into the pyruvate methyl group and by solvent kinetic isotope effects on pyruvate elimination catalyzed by AS.
journal_name
Biochemistryjournal_title
Biochemistryauthors
Culbertson JE,Chung Dh,Ziebart KT,Espiritu E,Toney MDdoi
10.1021/acs.biochem.5b00013subject
Has Abstractpub_date
2015-04-14 00:00:00pages
2372-84issue
14eissn
0006-2960issn
1520-4995journal_volume
54pub_type
杂志文章相关文献
BIOCHEMISTRY文献大全abstract::In the present report we studied the interaction between the skeletal muscle ryanodine receptor and the ubiquitous S100A1 Ca2+ binding protein. S100A1 did not affect equilibrium [3H]ryanodine binding to purified rabbit skeletal muscle terminal cisternae at 100 microM free [Ca2+]. At nanomolar free [Ca2+], however, S10...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi970160w
更新日期:1997-09-23 00:00:00
abstract::We have developed a model of glycophorin in a phospholipid bilayer membrane in order to study the thermodynamics of this system and to understand the detailed behavior of recent calorimetric data. We assume that the larger glycophorin polar group can be considered as either adopting a pancakelike conformation at the b...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00381a019
更新日期:1987-04-07 00:00:00
abstract::Bovine seminal ribonuclease (BS-RNase), the only dimeric protein among the pancreatic-like ribonucleases, is endowed with special structural features and with biological functions beyond enzymatic activity. In solution, the protein exists as an equilibrium mixture of two forms, with or without exchange (or swapping) o...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi0342517
更新日期:2003-07-29 00:00:00
abstract::The secretion of lung surfactant in alveolar type II cells is a complex process involving the fusion of lamellar bodies with the plasma membrane. This process is somewhat different from the exocytosis of hormones and neurotransmitters. For example, it is a relatively slower process, and lamellar bodies are very large ...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi036338y
更新日期:2004-03-30 00:00:00
abstract::Retinol (vitamin A alcohol) is a hydrophobic compound and distributes in vivo mainly between binding proteins and cellular membranes. To better clarify the nature of the interactions of retinol with these phases which have a high affinity for it, the thermodynamic parameters of these interactions were studied. The tem...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00468a014
更新日期:1990-04-24 00:00:00
abstract::Although the terms "excessive reactive oxygen species (ROS)" and "oxidative stress" are widely used, the implications of oxidative stress are often misunderstood. ROS are not a single species but a variety of compounds, each with unique biochemical properties and abilities to react with biomolecules. ROS cause activat...
journal_title:Biochemistry
pub_type: 杂志文章,评审
doi:10.1021/acs.biochem.6b00703
更新日期:2016-09-27 00:00:00
abstract::Progressive cerebral amyloid beta-protein (A beta) deposition is believed to play a central role in the pathogenesis of Alzheimer's disease (AD). Elevated levels of A beta(42) peptide formation have been linked to early-onset familial AD-causing gene mutations in the amyloid beta-protein precursor (A beta PP) and the ...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi0005456
更新日期:2000-08-01 00:00:00
abstract::The signaling apparatus that controls bacterial chemotaxis is composed of a core complex containing chemoreceptors, the histidine autokinase CheA, and the coupling protein CheW. Site-specific spin labeling and pulsed dipolar ESR spectroscopy (PDS) have been applied to investigate the structure of a soluble ternary com...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi100055m
更新日期:2010-05-11 00:00:00
abstract::The following peptide was synthesized by classical methods in solution: Ac-Asp-Phe-Leu-Ala-Glu-Gly-Gly-Gly-Val-Arg-Gly-Pro-Arg-Val-NHCH3 (F-8). The Michaelis-Menten parameters for the hydrolysis of the Arg-Gly bond in F-8 by thrombin were determined to be Kcat = 31 X 10(-11) M [(NIH unit/L) s]-1 and KM = 310 X 10(-6) ...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00287a002
更新日期:1983-08-30 00:00:00
abstract::The role of lateral diffusion in mitochondrial electron transport has been investigated by measuring the diffusion coefficients for lipid, cytochrome c, and cytochrome oxidase in membranes of giant mitoplasts from cuprizone-fed mice using the technique of fluorescence redistribution after photobleaching (FRAP). The di...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00331a017
更新日期:1985-05-07 00:00:00
abstract::Transition metal-transporting P1B-type CPx ATPases play crucial roles in mediating metal homeostasis and resistance in all cells. The degree to which N-terminal metal binding domains (MBDs) confer metal specificity to the transporter is unclear. We show that the two MBDs of the Zn/Cd/Pb effluxing pump Anabaena AztA ar...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi7006367
更新日期:2007-10-02 00:00:00
abstract::The chromatin structure encompassing the lysozyme gene domain in hen oviduct nuclei was studied by measuring the partitioning of coding and flanking sequences during chromatin fractionation and by analyzing the nucleosome repeat in response to micrococcal nuclease digestion. Following micrococcal nuclease digestion, n...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00350a033
更新日期:1986-01-28 00:00:00
abstract::Resonance energy transfer measurements provide a way to estimate distances between chromophores attached to different sites of macromolecules. There are two unknowns involved in resonance energy transfer measurements, the distance between two chromophores and their relative orientation. When static orientational disor...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00149a027
更新日期:1992-09-01 00:00:00
abstract::The composition of the molybdate-stabilized glucocorticoid receptor (GR) complex has been investigated with a monoclonal antibody against the steroid-binding Mr 94 000 (94K) GR protein. It was concluded that one antibody molecule binds one 94K GR molecule. This finding constituted the basis for calculating the number ...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00344a041
更新日期:1985-11-05 00:00:00
abstract::Heparan sulfate (HS) proteoglycans (PGs) interact with a number of extracellular signaling proteins, thereby playing an essential role in the regulation of many physiological processes. These interactions are important for both normal signal transduction and regulation of the tissue distribution of signaling molecules...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi6025424
更新日期:2007-04-03 00:00:00
abstract::We have employed high-performance liquid chromatography (HPLC) to investigate the syntheses of histones H1 and H1o as synchronized cells traverse from mitosis to S phase. Chinese hamster (line CHO) cells were synchronized by mitotic selection, and, at appropriate times, they were pulse labeled for 1 h with [3H]lysine....
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00329a031
更新日期:1985-04-09 00:00:00
abstract::N-Ethylmaleimide (NEM), which reacts readily with exposed sulfhydryl groups, has been shown to inhibit the activity of the microtubule (MT) motors kinesin, Ncd, and dynein. Currently, the mechanism of inhibition is not known for any of these proteins. To investigate the mechanism by which NEM inhibits Ncd, the recombi...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi990706+
更新日期:1999-08-17 00:00:00
abstract::Database searches indicated that the genome of Bacillus subtilis contains three different genes encoding RNase H homologues. The ypdQ gene encodes an RNase HI homologue with 132 amino acid residues, whereas the rnh and ysgB genes encode RNase HII homologues with 255 and 313 amino acid residues, respectively. RNases HI...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi982207z
更新日期:1999-01-12 00:00:00
abstract::Dihydroorotates deuteriated at both C5 and C6 have been prepared and used to probe the mechanism of the bovine liver mitochondrial dihydroorotate dehydrogenase. Primary deuterium isotope effects on kcat are observed with both (6RS)-[5(S)-2H]- and (6RS)-[6-2H] dihydroorotates (3 and 6, respectively); these effects are ...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00429a041
更新日期:1989-02-07 00:00:00
abstract::Most of the molybdoenzymes contain, in the amino-terminal region of their catalytic subunits, a conserved Cys group that in some cases binds an [Fe-S] cluster. In dissimilatory nitrate reductases, the first Cys residue of this motif is replaced by a conserved His residue. Site-directed mutagenesis of this residue (His...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi972858f
更新日期:1998-05-19 00:00:00
abstract::For screening a pool of potential substrates that load carrier domains found in nonribosomal peptide synthetases, large molecule mass spectrometry is shown to be a new, unbiased assay. Combining the high resolving power of Fourier transform mass spectrometry with the ability of adenylation domains to select their own ...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi052333k
更新日期:2006-02-14 00:00:00
abstract::Recently, it has been shown that the activation of the Drosophila EGF receptor (DER) by its natural ligand Spitz is inhibited by Argos [Schweitzer, R., et al. (1995) Nature 376, 699-702]. Argos and Spitz both have an EGF-like domain which in the case of Argos differs from that of Spitz and other EGF receptor agonists ...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi970227f
更新日期:1997-06-17 00:00:00
abstract::The reaction of nitric oxide (NO) with fast cytochrome bo from Escherichia coli has been studied by electronic absorption, MCD, and EPR spectroscopy. Titration of the enzyme with NO showed the formation of two distinct species, consistent with NO binding stoichiometries of 1:1 and 2:1 with observed dissociation consta...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi971481a
更新日期:1997-12-23 00:00:00
abstract::It had been previously reported that aromatic amines were not substrates for the bacterial quinoprotein methylamine dehydrogenase. In this study, benzylamine-dependent activity was also not observed in the steady-state assay of this enzyme with the artificial electron acceptor phenazine ethosulfate (PES). Benzylamines...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00128a012
更新日期:1992-04-07 00:00:00
abstract::The effect of ionic strength on enzyme activity and stability varies considerably between enzymes. Ionic strength is known to affect the catalytic activity of some alkaline phosphatases (APs), such as Escherichia coli AP, but how ions affect APs is debated. Here, we studied the effect of various ions on a cold-adapted...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/acs.biochem.7b00690
更新日期:2017-09-26 00:00:00
abstract::Two subfractions of low-density lipoproteins (LDL) were isolated from normal pig (Sus domesticus) serum by a combined method including precipitation, ultracentrifugation, and gel chromatography. The fractions recovered from the buoyant density ranges 1.020-1.050 and 1.050-1.090 g/mL, denoted as LDL1 and LDL2, respecti...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00514a038
更新日期:1981-05-26 00:00:00
abstract::Oligodeoxyribonucleotides 8-12 nucleotides in length whose sequences are complementary to the 5' end, the initiation codon regions, or the coding regions of rabbit globin mRNA were tested for their ability to inhibit translation in a rabbit reticulocyte lysate and in a wheat germ extract. The oligomers interact specif...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00343a015
更新日期:1985-10-22 00:00:00
abstract::Membrane vesicles from Mycobacterium phlei contain carrier proteins for proline, glutamine, and glutamic acid. The transport of proline is Na+ dependent and required substrate oxidation. A proline carrier protein was solubilized from the membrane vesicles by treatment with cholate and Triton X-100. Electron microscopi...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00578a015
更新日期:1979-05-29 00:00:00
abstract::Proteogenomic identification of translated small open reading frames in humans has revealed thousands of microproteins, or polypeptides of fewer than 100 amino acids, that were previously invisible to geneticists. Hundreds of microproteins have been shown to be essential for cell growth and proliferation, and many reg...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/acs.biochem.0c00672
更新日期:2020-10-27 00:00:00
abstract::Glutaraldehyde treatment of electroplax membrane preparations of Na,K-ATPase leads to irreversible changes in the enzymic behavior of the protein, which are not due to modification of the active site. When the glutaraldehyde treatment is carried out in a medium containing K+ and without Na+, the "K+-modified enzyme" s...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00288a016
更新日期:1983-09-13 00:00:00