Abstract：
:Site-specific mutagenesis has been used to create two mutant versions of aspartate transcarbamoylase. Arg-167 and Gln-231, both previously identified as interacting with the portion of the bisubstrate analogue N-(phosphonoacetyl)-L-aspartate (PALA) that corresponds to aspartate [Krause, K. L., Voltz, K. W., & Lipscomb, W. N. (1987) J. Mol. Biol. 193, 527-553], were replaced by glutamine and leucine, respectively. The Arg-167----Gln and the Gln-231----Leu enzymes show approximately 900-fold and 1500-fold reductions in the maximal observed specific activity, respectively. The aspartate concentration at half the maximal observed specific activity is increased 18-fold for the Gln-231----Leu enzyme compared to the value for the wild-type enzyme, but is altered little in the case of the Arg-167----Gln enzyme. The carbamoyl phosphate concentration at half the maximal activity is unchanged by either mutation, suggesting that these mutations result in only local changes to the aparatate binding site. Both mutations eliminate homotropic cooperativity; however, the Gln-231----Leu enzyme also has altered heterotropic interactions and no longer exhibits substrate inhibition. At relatively low concentrations of aspartate and saturating carbamoyl phosphate, PALA is able to activate the Gln-231----Leu enzyme, whereas the Arg-167----Gln enzyme is inhibited at PALA concentrations that normally activate the wild-type enzyme. Equilibrium binding measurements indicate that the Gln-231----Leu enzyme binds CTP approximately 10-fold more weakly than the wild-type enzyme, even though the mutation is some 70 A from the regulatory binding site.(ABSTRACT TRUNCATED AT 250 WORDS)
journal_name
Biochemistryjournal_title
Biochemistryauthors
Stebbins JW,Zhang Y,Kantrowitz ERdoi
10.1021/bi00468a003subject
Has Abstractpub_date
1990-04-24 00:00:00pages
3821-7issue
16eissn
0006-2960issn
1520-4995journal_volume
29pub_type
杂志文章相关文献
BIOCHEMISTRY文献大全abstract：:Rhodospirillum rubrum ribulose bisphosphate carboxylase contains two high affinity binding sites for pyridoxal phosphate and two catalytic sites per dimer. However, pyridoxal phosphate binding at only one site is sufficient for inactivation of both catalytic sites. In the presence of 20 mM bicarbonate, 10 mM magnesium...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi00600a024
更新日期：1978-04-04 00:00:00
abstract：:The binding of Ca2+ and the resulting change in catalytic specificity that allows phosphorylation of the calcium ATPase of sarcoplasmic reticulum by ATP were examined by measuring the amount of phosphoenzyme formation from [32P]ATP, or 45Ca incorporation into vesicles, after the simultaneous addition of ATP and EGTA a...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi00423a018
更新日期：1988-11-15 00:00:00
abstract：:The reactivity of aluminum and several other divalent and trivalent metallic cations toward chromatin from rat brain and liver has been investigated. Two criteria are used to determine the relative reactivity of these cations toward chromatin. The first involves the ability of the ions to compact the chromatin fibers ...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi00435a043
更新日期：1989-05-02 00:00:00
abstract：:The quaternary structures of Escherichia coli DNA-dependent RNA polymerase holenzyme (alpha 2 beta beta' sigma) and core enzyme (alpha 2 beta beta') have been investigated by chemical cross-linking with a cleavable bifunctional reagent, methyl 4-mercaptobutyrimidate, and noncleavable reagents, dimethyl suberimidate an...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi00634a008
更新日期：1977-07-26 00:00:00
abstract：:The fluorescence polarization intensities from fluorescent probes and the electron paramagnetic resonance spectra from spin probes, specifically modifying elements of a biological assembly such as myosin sulfhydryl 1 (SH1) in muscle fibers, are interpreted in terms of probe order parameters using a model-independent m...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi00116a029
更新日期：1992-01-14 00:00:00
abstract：:The covalent affinity probe maltosyl isothiocyanate (MITC) has been used previously to identify the glucose transporter of human erythrocytes as a component of band 3. By use of limited proteolysis, the site on the Mr 100 000 protein to which MITC attaches has been localized to a 17 000-dalton region near the center o...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi00331a001
更新日期：1985-05-07 00:00:00
abstract：:The rates of inactivation of BF1 adenosinetriphosphatase (BF1-ATPase) from Escherichia coli by 7-chloro-4-nitro-2,1,3-benzoxadiazole, 1-fluoro-2,4-dinitrobenzene, 2,4,6-trinitrobenzenesulfonate, phenylglyoxal, and N,N'-dicyclohexylcarbodiimide have been measured in the presence and absence of various concentrations of...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi00531a011
更新日期：1982-01-19 00:00:00
abstract：:Phosphatidic (PtdOH) acid formation is recognized as an important step in numerous signaling pathways in both plants and mammals. To study the role of this lipid in signaling pathways, it is of major interest to be able to increase the amount of this lipid directly. Therefore, "caged" PtdOH was synthesized, which rele...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi0351460
更新日期：2004-04-13 00:00:00
abstract：:The self-assembly of beta(2)-microglobulin into fibrils leads to dialysis-related amyloidosis. pH-mediated partial unfolding is required for the formation of the amyloidogenic intermediate that then self-assembles into amyloid fibrils. Two partially folded intermediates of beta(2)-microglobulin have been identified ex...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi050731h
更新日期：2005-12-13 00:00:00
abstract：:Mycobacterial Ser/Thr kinase, PknB, is essential for the growth of the pathogen. Unphosphorylated PknB is catalytically inactive, and its activation requires autophosphorylation of Thr residues on the activation loop. Autophosphorylation can in principle take place via two distinct mechanisms. Intermolecular trans aut...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi500245v
更新日期：2014-07-22 00:00:00
abstract：:The effect of DnaB helicase on the initiation specificity of primase was studied biochemically using a series of single-stranded DNA templates in which each nucleotide of the trinucleotide d(CTG) initiation sequence was systematically varied. DnaB helicase accelerated the rate of primer syntheisis, prevented "overlong...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi991555d
更新日期：2000-02-01 00:00:00
abstract：:3-Deoxy-d-manno-octulosonate 8-phosphate (KDO8P) synthase catalyzes the condensation of arabinose 5-phosphate (A5P) and phosphoenolpyruvate (PEP) to form KDO8P, a key precursor in the biosynthesis of the endotoxin of Gram-negative bacteria. Earlier studies have established that the condensation occurs with a syn addit...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi901341h
更新日期：2009-12-15 00:00:00
abstract：:A molecular model has been built of the equine infectious anemia virus (EIAV) proteinase on the basis of the crystal structures of the related Rous sarcoma virus (RSV) and human immunodeficiency virus (HIV) proteinases. The 104 residue long EIAV proteinase has 30 identical and 11 similar amino acids compared to those ...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi00064a019
更新日期：1993-04-06 00:00:00
abstract：:Chemical biosensors, for which chemical detection triggers a fluorescent signal, have the potential to accelerate the screening of noncolorimetric chemicals produced by microbes, enabling the high-throughput engineering of enzymes and metabolic pathways. Here, we engineer a G-protein-coupled receptor (GPCR)-based sens...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/acs.biochem.7b00605
更新日期：2017-10-17 00:00:00
abstract：:Mistic is an unusual membrane protein from Bacillus subtilis. It appears to fold and insert autonomously into a lipid bilayer and has been suggested as a tool that aids the targeting of eukaryotic membrane proteins to bacterial membranes. The NMR structure of Mistic in detergent (LDAO) micelles has revealed it to be a...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi0608818
更新日期：2006-08-01 00:00:00
abstract：:Sedimentation experiments with closed circular duplex PM2 deoxyribonucleic acid (DNA) and viscosity measurements with sonicated rodlike DNA fragments have been performed to investigate unwinding and extension of the DNA helix associated with binding of homologous series of diacridines. When the acridine nuclei are lin...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi00566a026
更新日期：1980-12-09 00:00:00
abstract：:The chromatin-associated high-mobility group (HMG) proteins of the plant HMGB family are characterized by a central HMG-box domain that is flanked by a basic N-terminal and an acidic C-terminal domain. By functional interaction with certain transcription factors, HMGB proteins contribute to transcriptional regulation....
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi6024947
更新日期：2007-05-29 00:00:00
abstract：:A mechanism by which the Klenow fragment of DNA polymerase I monitors the geometry of the base pairs may involve hydrogen bonds between the polymerase and the minor groove of the nascent base pair. The involvement of the 3-position of guanine in the template strand was examined by synthesizing oligodeoxynucleotides co...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi971253g
更新日期：1997-10-28 00:00:00
abstract：:Fourier transform infrared (FTIR) spectroscopy and a library of FTIR marker bands have been used to examine the structure and relative flexibilities conferred by different flanking sequences on the EcoRI binding site. This approach allowed us to examine unique peaks and subtle changes in the spectra of d(AAAGAATTCTTT)...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi8015235
更新日期：2009-02-17 00:00:00
abstract：:The photoautotrophic freshwater cyanobacterium Synechococcus elongatus is widely used as a chassis for biotechnological applications as well as a photosynthetic bacterial model. In this study, a method for expanding the genetic code of this cyanobacterium has been established, thereby allowing the incorporation of unn...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/acs.biochem.7b00131
更新日期：2017-04-25 00:00:00
abstract：:Aqueous suspensions of dark-adapted bacteriorhodopsin (bR560) in the purple membrane of Halobacterium halobium are exposed to rapid jumps to high pH. Optical and resonance Raman measurements are carried out by using flow and stationary methods. Above pH congruent to 11.5 bR560 starts to be reversibly converted to a sp...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi00263a019
更新日期：1982-09-28 00:00:00
abstract：:Two thiol-activated endopeptidases with pH optima near pH 7.5 were isolated from the supernatant fraction of rabbit brain homogenates by DEAE-cellulose chromatography, gel filtration and isoelectrofocusing. Peptide bond hydrolysis was measured quantitatively by ion-exchange chromatography with an amino acid analyzer. ...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi00654a026
更新日期：1976-05-04 00:00:00
abstract：:Type II topoisomerases are responsible for DNA unlinking during DNA replication and chromosome segregation. Although eukaryotic enzymes are homodimers and prokaryotic enzymes are heterotetramers, both prokaryotic and eukaryotic type II topoisomerases belong to a single protein family. The amino- and carboxyl-terminal ...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi0155201
更新日期：2001-07-24 00:00:00
abstract：:Raman spectra of phycocyanobilin, phycocyanin, and allophycocyanin were obtained at resonance with their visible and near-UV transitions. These spectra were empirically assigned with the help of 14N- and 15N-isotopic substitutions and comparisons with resonance Raman spectra of phycoerythrin. These results confirm the...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi00205a019
更新日期：1994-10-04 00:00:00
abstract：:We have studied the hydrogen-exchange kinetics of hemoglobin A0 as a function of ligand, CO, saturation. In the noncooperative system, azide binding to methemoglobin, the alterations in exchange kinetics are proportional to the average degree of ligation. However, in the case of CO binding to deoxyhemoglobin the chang...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi00297a015
更新日期：1984-01-17 00:00:00
abstract：:Several diseases, such as cancer, are characterized by acidification of the extracellular environment. Acidosis can be employed as a target to specifically direct therapies to the diseased tissue. We have used first principles to design an acidity-triggered rational membrane (ATRAM) peptide with high solubility in sol...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/acs.biochem.5b00856
更新日期：2015-11-03 00:00:00
abstract：:Phage T4 gene 32 protein (gp32) is a zinc metalloprotein which binds cooperatively and preferentially to single-stranded nucleic acids and functions as a replication and recombination accessory protein. Zn(II) coordination by gp32 employs a His-Cys3 metal ligand donor set derived from the His64-X12-Cys77-X9-Cys87-X2-C...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi9617769
更新日期：1997-01-28 00:00:00
abstract：:We have developed a panel of antibodies specific for the alpha 1, alpha 2, alpha 3, and beta subunits of the rat Na,K-ATPase. TrpE-alpha subunit isoform fusion proteins were used to generate three antisera, each of which reacted specifically with a distinct alpha subunit isotype. Western blot analysis of rat tissue mi...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi00437a002
更新日期：1989-05-30 00:00:00
abstract：:Runx proteins constitute a family of mammalian transcription factors that interact with DNA through their evolutionarily conserved Runt domain. CBFbeta, alternatively denoted PEBP2beta, is the non-DNA-binding heterodimer partner and acts to enhance the DNA binding affinity of Runx proteins. Runx proteins and CBFbeta a...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi010713+
更新日期：2001-09-25 00:00:00
abstract：:The following polynucleotides containing the antibiotic tubercidin (Tu; 4-amino-7-beta-D-ribofuranosylpyrrolo-[2,3-d]pyrimidine) were enzymatically synthesized by polymerization of adenosine 5'-diphosphate-tubercidin 5'-diphosphate mixtures with polynucleotide phosphorylase: poly(A2,Tu), poly(A,Tu2), and poly(Tu). The...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi00512a030
更新日期：1981-04-28 00:00:00
