Abstract:
:The EcoRV restriction/modification system consists of two enzymes that recognize the DNA sequence GATATC. The EcoRV restriction endonuclease cleaves DNA at this site, but the DNA of Escherichia coli carrying the EcoRV system is protected from this reaction by the EcoRV methyltransferase. However, in vitro, the EcoRV nuclease also cleaves DNA at most sites that differ from the recognition sequence by one base pair. Though the reaction of the nuclease at these sites is much slower than that at the cognate site, it still appears to be fast enough to cleave the chromosome of the cell into many fragments. The possibility that the EcoRV methyltransferase also protects the noncognate sites on the chromosome was examined. The modification enzyme methylated alternate sites in vivo, but these were not the same as the alternate sites for the nuclease. The excess methylation was found at GATC sequences, which are also the targets for the dam methyltransferase of E. coli, a protein that is homologous to the EcoRV methyltransferase. Methylation at these sites gave virtually no protection against the EcoRV nuclease: even when the EcoRV methyltransferase had been overproduced, the cellular DNA remained sensitive to the EcoRV nuclease at its noncognate sites. The viability of E. coli carrying the EcoRV restriction/modification system was found instead to depend on the activity of DNA ligase. Ligase appears to proofread the EcoRV R/M system in vivo: DNA, cut initially in one strand at a noncognate site for the nuclease, is presumably repaired by ligase before the scission of the second strand.
journal_name
Biochemistryjournal_title
Biochemistryauthors
Taylor JD,Goodall AJ,Vermote CL,Halford SEdoi
10.1021/bi00500a003subject
Has Abstractpub_date
1990-12-04 00:00:00pages
10727-33issue
48eissn
0006-2960issn
1520-4995journal_volume
29pub_type
杂志文章相关文献
BIOCHEMISTRY文献大全abstract::FixL is a heme-based oxygen-sensing histidine kinase that induces the expression of nitrogen fixation genes under hypoxic conditions. Oxygen dissociation from heme iron in the sensor domain of FixL initiates protein conformational changes that are transmitted to the histidine kinase domain, activating autophosphorylat...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/acs.biochem.6b00405
更新日期:2016-07-26 00:00:00
abstract::Hepatic microsomal NADPH-cytochrome P-450 reductase was solubilized from rabbit liver microsomes in the presence of detergents and purified to homogeneity by column chromatography. The purified reductase had a molecular weight of 78 000 and contained 1 mol each of FAD and FMN per mol of enzyme. On reduction with NADPH...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00604a032
更新日期:1978-05-30 00:00:00
abstract::A short chain dehydrogenase like l-threonine 3-dehydrogenase (SDR-TDH) from metagenome data (mtTDH) was identified by database mining. Its enzymatic properties suggested that mtTDH has unique characteristics relative to other SDR-TDHs, including two mesophilic and thermophilic SDR-TDHs identified in this study. The ac...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/acs.biochem.7b00832
更新日期:2017-10-31 00:00:00
abstract::The nuclease hypersensitivity element III(1) (NHE III(1)) of the c-MYC promoter strongly controls the transcriptional activity of the c-MYC oncogene. The purine-rich strand of the NHE III(1) element has been shown to be a silencer element for c-MYC transcription upon formation of a G-quadruplex structure. We have dete...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi048242p
更新日期:2005-02-15 00:00:00
abstract::Colibactins are genotoxic secondary metabolites whose biosynthesis is encoded in the clb gene cluster harbored by certain strains of gut commensal Escherichia coli. Using synthetic colibactin analogues, we previously provided evidence that colibactins alkylate DNA by addition of a nucleotide to an electrophilic cyclop...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/acs.biochem.8b01023
更新日期:2018-11-13 00:00:00
abstract::cis peptide bonds in proteins are often rate-limiting steps in protein folding or conformational change and are frequently stabilized by metal ions. In the collagen-binding domain of Clostridium histolyticum collagenase, the binding of calcium ions triggers the formation of a cis peptide bond. We present free energy s...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi1007047
更新日期:2010-06-29 00:00:00
abstract::Phospholipid transfer protein (PLTP) is expressed by macrophage-derived foam cells in human atherosclerotic lesions, suggesting a regulatory role for PLTP in cellular cholesterol homeostasis. However, the exact role of PLTP in the reverse cholesterol transport pathway is not known. PLTP is present in plasma as two for...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi700833h
更新日期:2007-10-23 00:00:00
abstract::The amide hydrogens that are exposed to solvent in the high-resolution X-ray structures of ubiquitin, FK506-binding protein, chymotrypsin inhibitor 2, and rubredoxin span a billion-fold range in hydroxide-catalyzed exchange rates which are predictable by continuum dielectric methods. To facilitate analysis of transien...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi901219x
更新日期:2009-10-06 00:00:00
abstract::Pig kidney general acyl-CoA dehydrogenases forms the blue neutral radical on dithionite or photochemical reduction (Thorpe, C., Matthews, R. G., & Williams, C. H. (1979) Biochemistry 18, 331-337] in accord with its classification as a flavoprotein dehydrogenase. However, dithionite reduction of the enzyme in the prese...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00520a024
更新日期:1981-08-18 00:00:00
abstract::X-ray crystallographic data to 1.9-A resolution were collected on sperm whale metmyoglobin equilibrated with 7 atm of xenon gas. The results indicate four xenon sites of occupancy from 0.45 to 1.0. These sites are located in interior spaces or packing defects of the myoglobin molecule. The effects of the bound xenon o...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00308a002
更新日期:1984-06-19 00:00:00
abstract::Monoamine oxidase B (MAO B) is an integral protein of the outer mitochondrial membrane that is involved in the deamination of vasoactive and neuroactive amines. The oxidation of these amine substrates requires the cofactor FAD, which is covalently bound to Cys-397 of human MAO B. Previously, Glu-34 and Tyr-44 of MAO B...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi9806910
更新日期:1998-09-01 00:00:00
abstract::We have measured the concentration of mRNAs coding for immunoglobulins, k and lambda type light chains and gamma 1 type heavy chain, in mouse spleen cells activated by bacterial lipopolysaccharide or sheep red blood cells. These mRNAs were quantitated by hybridization to radioactive DNA complementary to highly purifie...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00645a018
更新日期:1977-12-27 00:00:00
abstract::The alpha, beta, and gamma subunits of the receptor with high affinity for immunoglobulin E were isolated and their compositions assessed by direct amino acid analysis and by incorporation of radioactive precursors. The compositions show no unusual features other than a rather high content of tryptophan in the alpha c...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00383a024
更新日期:1987-05-05 00:00:00
abstract::The effect of both antimitotic drugs and nucleotide analogues on the magnesium-induced self-association of purified tubulin into 42S double rings has been examined by sedimentation velocity. In the absence of magnesium, all complexes sedimented as the 5.8S species. The binding of colchicine to tubulin led to a small b...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00149a044
更新日期:1992-09-01 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::Solid-state NMR spectroscopy was employed to study the molecular dynamics of the colicin Ia channel domain in the soluble and membrane-bound states. In the soluble state, the protein executes small-amplitude librations (with root-mean-square angular fluctuations of 0-10 degrees ) in the backbone and larger-amplitude m...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi0027231
更新日期:2001-06-26 00:00:00
abstract::The radiation inactivation method was used to study the size of acetylcholine receptors in the intact membrane-bound state. This technique was reinvestigated, and modifications were made which remove substantial difficulties affecting previous applications of it to such proteins. The molecular size was deduced here by...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00538a033
更新日期:1982-04-27 00:00:00
abstract::Electrostatic interactions play a key role in enzyme catalytic function. At long range, electrostatics steer the incoming ligand/substrate to the active site, and at short distances, electrostatics provide the specific local interactions for catalysis. In cases in which electrostatics determine enzyme function, orthol...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi026918f
更新日期:2003-04-01 00:00:00
abstract::The inhibitory potency of 3'-azido-3'-deoxythymidine 5'-triphosphate (AZTTP) against HIV-1 reverse transcriptase (HIV-1 RT) has been further evaluated. The results indicate that the previously reported low Ki values for AZTTP against HIV-1 RT (2.35 nM) are due neither to the to the direct tight binding of AZTTP to HIV...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00120a013
更新日期:1992-02-11 00:00:00
abstract::Adeno-associated virus (AAV) nonstructural proteins Rep78 and Rep68 carry out all DNA transactions that regulate the AAV life cycle. They share two multifunctional domains: an N-terminal origin binding/nicking domain (OBD) from the HUH superfamily and a SF3 helicase domain. A short linker of ∼20 amino acids that is cr...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/acs.biochem.5b00610
更新日期:2015-09-29 00:00:00
abstract::Phosphorylation of G protein-coupled receptors (GPCRs) terminates their ability to couple with and activate G proteins by increasing their affinity for arrestins. Unfortunately, detailed information regarding how GPCRs interact with the kinases responsible for their phosphorylation is still limited. Here, we purified ...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/acs.biochem.6b00328
更新日期:2016-06-07 00:00:00
abstract::3-Deoxy-d- manno-2-octulosonate-8-phosphate (KDO8P) synthase catalyzes the first step of lipopolysaccharide biosynthesis, namely condensation of phosphoenolpyruvate (PEP) with arabinose 5-phosphate (A5P), to produce KDO8P. We have characterized Campylobacter jejuni KDO8P synthase and its inhibition by KDO8P oxime. It ...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/acs.biochem.8b00748
更新日期:2018-09-11 00:00:00
abstract::G-protein-coupled receptors (GPCRs) represent the largest class of drug targets, accounting for more than 40% of marketed drugs; however, discovery efforts for many GPCRs have failed to provide viable drug candidates. Historically, drug discovery efforts have focused on developing ligands that act at the orthosteric s...
journal_title:Biochemistry
pub_type: 杂志文章,评审
doi:10.1021/bi200129s
更新日期:2011-04-05 00:00:00
abstract::The Y70F mutant of aspartate aminotransferase has reduced affinity for coenzymes compared to the wild type. The equilibrium dissociation constants for pyridoxamine phosphate (PMP) holoenzymes, KPMPdiss, were determined from the association and dissociation rate constants to be 1.3 nM and 30 nM for the wild type and mu...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00244a014
更新日期:1991-07-30 00:00:00
abstract::Proteins denature at low pH because of intramolecular electrostatic repulsions. The addition of salt partially overcomes this repulsion for some proteins, yielding a collapsed conformation called the A-state. A-states have characteristics expected for the molten globule, a notional kinetic protein folding intermediate...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi981364v
更新日期:1998-12-01 00:00:00
abstract::The mechanism of the slow refolding reactions of four different pancreatic ribonucleases from ox, sheep, red deer, and roe deer has been investigated. Refolding kinetics of these proteins were very similar. In particular, a native-like intermediate, IN, was shown to be populated on the slow refolding pathway of all ri...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00336a005
更新日期:1985-07-16 00:00:00
abstract::Sufiredoxins (Srx) repair the inactivated forms of typical two-Cys peroxiredoxins (Prx) implicated in hydrogen peroxide-mediated cell signaling. The reduction of the cysteine sulfinic acid moiety within the active site of the Prx by Srx involves novel sulfur chemistry and the use of ATP and Mg(2+). The 1.65 A crystal ...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi050131i
更新日期:2005-06-21 00:00:00
abstract::The three-dimensional structure of the duplex formed by the association of the unnatural oligonucleotide alpha-d(TCTAAACTC) covalently linked to an acridine derivative (m5Acr) with its natural and parallel complementary sequence beta-d(AGATTTGAG) was investigated by nuclear magnetic resonance spectroscopy and constrai...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00472a031
更新日期:1990-05-22 00:00:00
abstract::Monomeric sarcosine oxidase (MSOX) binds the L-proline zwitterion (pKa = 10.6). The reactive substrate anion is generated by ionization of the ES complex (pKa = 8.0). Tyr317 was mutated to Phe to determine whether this step might involve proton transfer to an active site base. The mutation does not eliminate the ioniz...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi051898d
更新日期:2005-12-27 00:00:00
abstract::Glu58 is known to participate in phosphodiester transesterification catalyzed by the enzyme RNase T1. For Glu58 RNase T1, an altered mechanism has been proposed in which His40 replaces Glu58 as the base catalyst [Steyaert, J., Hallenga, K., Wyns, L., & Stanssens, P. (1990) Biochemistry 29, 9064-9072]. Glu58Ala Rnase T...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00173a006
更新日期:1994-02-22 00:00:00