Abstract:
:Vaccinia DNA topoisomerase, a 314 amino acid type I enzyme, catalyzes the cleavage and rejoining of DNA strands through a DNA-(3'-phosphotyrosyl)-enzyme intermediate formed at a specific target sequence, 5'-(C/T)CCTT downward arrow. To identify amino acids that participate in the DNA binding and transesterification steps, we introduced alanine substitutions at 18 positions within a centrally located 27 amino acid segment (181-RLYKPLLKLTDDSSPEEFLFNKLSERK-207) and at 8 positions near the N-terminus (1-MRALFYKDGK-10). All mutant proteins except two displayed wild-type activity in relaxing supercoiled DNA. F200A and S204A exhibited reduced rates of relaxation and were subjected to a kinetic analysis of the strand cleavage reaction under single-turnover and equilibrium conditions. The F200A and S204A mutations reduced the rate of single-turnover DNA cleavage by factors of 5 and 70, respectively. Both mutations shifted the cleavage-religation equilibrium in favor of the noncovalently bound state. The S204A mutation reduced the affinity of topoisomerase for CCCTT-containing DNA, but did not alter the site-specificity of DNA cleavage. Vaccinia residue Ser-204, which is conserved in all poxvirus topoisomerases, but not in the cellular homologues, may contribute to the unique cleavage site specificity of the poxvirus enzymes. Phe-200 is conserved in all members of the type IB topoisomerase family.
journal_name
Biochemistryjournal_title
Biochemistryauthors
Wang LK,Wittschieben J,Shuman Sdoi
10.1021/bi970498qsubject
Has Abstractpub_date
1997-07-01 00:00:00pages
7944-50issue
26eissn
0006-2960issn
1520-4995pii
bi970498qjournal_volume
36pub_type
杂志文章相关文献
BIOCHEMISTRY文献大全abstract::Characterization of the complete gene sequence encoding the alpha-galactosidase from Phanerochaete chrysosporium confirms that this enzyme is a member of glycosyl hydrolase family 27 [Henrissat, B., and Bairoch, A. (1996) Biochem. J. 316, 695-696]. This family, together with the family 36 alpha-galactosidases, forms g...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi0008074
更新日期:2000-08-15 00:00:00
abstract::Recombinant human 3'-phosphoadenosine 5'-phosphosulfate (PAPS) synthetase, isoform 1 (brain), was purified to near-homogeneity from an Escherichia coli expression system and kinetically characterized. The native enzyme, a dimer with each 71 kDa subunit containing an adenosine triphosphate (ATP) sulfurylase and an aden...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi049827m
更新日期:2004-04-13 00:00:00
abstract::NSC 613862 (S)-(-) and NSC 613863 (R)-(+) are the two chiral isomers of ethyl-5-amino-2-methyl-1,2-dihydro-3-phenylpyrido[3, 4-b]pyrazin-7-yl carbamate. Both compounds bind to tubulin in a region that overlaps the colchicine site. They induce formation of abnormal polymers from purified GTP-Mg-tubulin, the active asse...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi970568t
更新日期:1998-01-13 00:00:00
abstract::Direct chemical titrations of reduced, purified cytochrome aa3 were monitored at 604 nm. Anaerobic oxidation by potassium ferricyanide or 1,1'-bis(hydroxymethyl)-ferricinium ion was compared with the natural substrate, molecular oxygen. The four electrons from reduced cytochrome aa3 were donated to one oxygen molecule...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00626a014
更新日期:1977-04-05 00:00:00
abstract::For the elucidation of the mechanism of steroid hormone receptor activation, the hydrodynamic properties of the unactivated and activated forms of the nonproteolyzed glucocorticoid receptor from the mouse AtT-20 pituitary tumor cell line were determined. The unactivated, molybdate-stabilized receptor has the following...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00277a038
更新日期:1983-04-12 00:00:00
abstract::The purL gene of Escherichia coli encoding the enzyme formylglycinamidine ribonucleotide (FGAM) synthetase which catalyzes the conversion of formylglycinamide ribonucleotide (FGAR), glutamine, and MgATP to FGAM, glutamate, ADP, and Pi has been cloned and sequenced. The mature protein, as deduced by the structural gene...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00432a017
更新日期:1989-03-21 00:00:00
abstract::Prion diseases are associated with a conformational switch in the prion protein (PrP) from its normal cellular form (denoted PrP(C)) to a disease-associated "scrapie" form (PrP(Sc)). A number of PrP(Sc)-like conformations can be generated by incubating recombinant PrP(C) at low pH, indicating that protonation of key r...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi100572j
更新日期:2010-10-12 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::(Z)-3-(Fluoromethyl)phosphoenolpyruvate has been synthesized in nine chemical steps from glyoxylic acid. The compound is stable at pH 3, but at pH 8 it decomposes within seconds to give 2-oxo-3-butenoate. When 3-(fluoromethyl)phosphoenolpyruvate is added to a solution of phosphoenolpyruvate carboxylase or pyruvate kin...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00404a039
更新日期:1988-02-23 00:00:00
abstract::We reported previously that cdc2 kinase decreased the microtubule-stabilizing ability of a major HeLa cell microtubule-associated protein, MAP4, by phosphorylation in vitro [Ookata, K., et al. (1995) J. Cell Biol. 128, 849-862]. An important question raised by this study is whether MAP4 is indeed phosphorylated by cdc...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi971251w
更新日期:1997-12-16 00:00:00
abstract::The specific effect of the binding of IF2 and initiator fMET-tRNA(fMet) on Escherichia coli 16S rRNA has been probed by phosphate alkylation with ethylnitrosourea. The results show that IF2 does not significantly shield portions of 16S rRNA but induces both reductions and enhancements of reactivity scattered in the en...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00487a023
更新日期:1990-09-04 00:00:00
abstract::Human immunodeficiency virus type 1 protease (HIV-1 PR) is an essential enzyme in the HIV-1 life cycle. As such, this protein represents a major drug target in AIDS therapy, but emerging resistance to antiretroviral inhibitor cocktails, caused by high viral mutation rates, represents a significant challenge in AIDS tr...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi100569u
更新日期:2010-05-18 00:00:00
abstract::Bacterioferritins are members of a class of spherical shell-like iron storage proteins that catalyze the oxidation and hydrolysis of iron at specific sites inside the protein shell, resulting in formation of a mineral core of hydrated ferric oxide within the protein cavity. Electrode oximetry/pH stat was used to study...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi992631f
更新日期:2000-04-25 00:00:00
abstract::An X-ray structure analysis of a crystal of mutant Asp229----Ala of cyclodextrin glycosyltransferase from Bacillus circulans (Ec 2.4.1.19) that had been shortly exposed to beta-cyclodextrin showed density corresponding to a maltose bound at the catalytic center. The crystal structure was refined to an R-factor of 18.7...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00152a009
更新日期:1992-09-22 00:00:00
abstract::The reaction of ferric cytochrome c peroxidase (CcP) from Saccharomyces cerevisiae with peroxide produces compound I, characterized by both an oxyferryl iron center and a protein-based free radical. The electron paramagnetic resonance (EPR) signal of the CcP compound I radical can be resolved into a broad majority com...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00221a036
更新日期:1991-02-19 00:00:00
abstract::Molecular dynamics simulations employing a molecular mechanics (MM) force field and hybrid quantum mechanics (QM) and MM (QM/MM) have been carried out to investigate the product specificity and mechanism of the histone H4 lysine 20 (H4-K20) methylation by human histone lysine methyltransferase SET8. At neutral pH, the...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi800244s
更新日期:2008-06-24 00:00:00
abstract::The number of self-cleaving ribozymes has increased sharply in recent years, giving rise to elaborations of the four known ribozyme catalytic strategies, α, β, γ, and δ. One such extension is utilized by the twister ribozyme, which is hypothesized to conduct δ, or general acid catalysis, via N3 of the syn adenine +1 n...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/acs.biochem.9b00742
更新日期:2019-12-03 00:00:00
abstract::Herpesvirus saimiri encodes a tyrosine kinase interacting protein (Tip) that binds to T-cell-specific tyrosine kinase Lck via multiple sequence motifs and controls its activity. The regulation of Lck by Tip represents a key mechanism in the transformation of human T-lymphocytes during herpesviral infection. In this st...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi0485068
更新日期:2004-11-30 00:00:00
abstract::The conformational properties of the magainin family of antimicrobial peptides in aqueous solution and in model membranes have been probed by Fourier transform infrared spectroscopy. The magainins were found to be structureless in aqueous solution at neutral pD, confirming other studies by Raman and circular dichroism...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00147a012
更新日期:1992-08-18 00:00:00
abstract::Alanine scanning mutagenesis, double mutant cycles, and X-ray crystallography were used to characterize the interface between the anti-hen egg white lysozyme (HEL) antibody D1.3 and HEL. Twelve out of the 13 nonglycine contact residues on HEL, as determined by the high-resolution crystal structure of the D1.3-HEL comp...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi980148j
更新日期:1998-06-02 00:00:00
abstract::(S)-Mandelate dehydrogenase from Pseudomonas putida belongs to a FMN-dependent enzyme family that oxidizes (S)-alpha-hydroxyacids. Despite a high degree of sequence and structural similarity, this family can be divided into three subgroups based on the different oxidants utilized in the second oxidative half-reaction....
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi049005p
更新日期:2004-08-24 00:00:00
abstract::Phospholipase A(2) (PLA(2)) (E. C. 3.1.1.4) is a common enzyme in the two-way cascade mechanism leading to the production of proinflammatory compounds known as eicosanoids. The binding of phospholipase A(2) to the membrane surface and hydrolysis of phospholipids are thought to involve the formation of a hydrophobic ch...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi035076x
更新日期:2003-10-14 00:00:00
abstract::Peptidylglycine alpha-hydroxylating monooxygenase (PHM) is a copper, ascorbate, and molecular oxygen dependent enzyme that catalyzes the first step leading to the C-terminal amidation of glycine-extended peptides. The catalytic core of PHM (PHMcc), refined to residues 42-356 of the PHM protein, was expressed at high l...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi9708747
更新日期:1997-09-09 00:00:00
abstract::To study the effects of methylation damage on DNA replication in vitro, the plasmid pSVori containing the SV40 origin of replication was reacted with N-methyl-N-nitrosourea and used as a substrate for SV40 T antigen dependent replication by HeLa cell extracts. The plasmid was methylated with a range of N-methyl-N-nitr...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00212a035
更新日期:1993-12-14 00:00:00
abstract::Human placental lipocortin is a high-affinity substrate for rat brain protein kinase C in vitro with phosphorylation occurring on serine and threonine residues in a ratio of approximately 2 to 1. Comparison of the ability of various N-terminal-truncated derivatives of lipocortin to serve as phosphorylation substrates,...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00412a008
更新日期:1988-06-14 00:00:00
abstract::Lysine 2,3-aminomutase from Clostridia catalyzes the interconversion of L-lysine and L-beta-lysine. The enzyme contains iron-sulfur clusters and is activated by pyridoxal 5'-phosphate and S-adenosylmethionine, all of which participate in catalysis. Current spectroscopic evidence implicates two substrate-based organic ...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi960850k
更新日期:1996-08-27 00:00:00
abstract::The structure and function of iron(II)-ruthenium(II) hybrid hemoglobins alpha(Ru-CO)2 beta(Fe)2 and alpha(Fe)2 beta(Ru-CO)2, which can serve as models for the intermediate species of the oxygenation step in native human adult hemoglobin, were investigated by measuring oxygen equilibrium curves and the Fe(II)-N epsilon...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00447a050
更新日期:1989-10-17 00:00:00
abstract::Hybridization experiments with variants of an oligomeric protein often provide important information regarding subunit structure, function, and interactions. In some systems, however, the variants are so similar electrophoretically and chromatographically that purification of individual hybrids is not feasible. Theref...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00646a009
更新日期:1976-01-13 00:00:00
abstract::β-2-Microglobulin (β2m) forms amyloid fibrils in the joints of patients undergoing dialysis treatment as a result of kidney failure. One of the ways in which β2m can be induced to form amyloid fibrils in vitro is via incubation with stoichiometric amounts of Cu(II). To better understand the structural changes caused b...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/acs.biochem.6b01198
更新日期:2017-02-28 00:00:00
abstract::R67 dihydrofolate reductase (DHFR) is a type II DHFR produced by bacteria as a resistance mechanism to the increased clinical use of the antibacterial drug trimethoprim. Type II DHFRs are not homologous in either sequence or structure with chromosomal DHFRs. The type II enzymes contain four identical subunits which fo...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi0026425
更新日期:2001-04-10 00:00:00