Abstract:
:Bacteriophage T7 RNA polymerase is a single-subunit enzyme which has a C-terminal amino acid sequence of Phe-Ala-Phe-Ala883 (FAFA883). Closely related hydrophobic sequences are present at the C termini of seven other single-subunit RNA polymerases, including the mitochondrial RNA polymerase. Mutations at any of the four C-terminal residues depress initiation rates of T7 RNA polymerase from 50 to 95%, accompanied by large increases in the K(m) values for the initiating nucleotide, GTP, as well as the K(m)'s for promoter DNA. The dramatic drops in initiation rates shown by the mutant enzymes remain after correcting for any alteration in saturation of the enzyme by the initiating nucleotide or the promoter DNA resulting from the changes in K(m). In contrast, the high processivity of the enzyme is not altered by mutations in the last four residues. However, the propensity for the enzyme to add an untemplated nucleotide at the 3'-ends of transcripts is abolished by the A880AFA883 mutation. The C-terminal FAFA sequence or foot appears to interact both with the initiating NTP and with the most downstream nucleotides of the promoter, possibly through hydrophobic interactions with the minor groove, in the region where free radical footprinting of the polymerase-promoter DNA complex suggests that the enzyme binds across the minor groove.
journal_name
Biochemistryjournal_title
Biochemistryauthors
Gardner LP,Mookhtiar KA,Coleman JEdoi
10.1021/bi962397isubject
Has Abstractpub_date
1997-03-11 00:00:00pages
2908-18issue
10eissn
0006-2960issn
1520-4995pii
bi962397ijournal_volume
36pub_type
杂志文章相关文献
BIOCHEMISTRY文献大全abstract::The structure and folding of a novel human insulin mutant, [Thr(B27) --> Pro, Pro(B28) --> Thr]insulin (PT insulin), in aqueous solution and in mixtures of water and 2,2,2-trifluoroethanol (TFE) have been studied by NMR spectroscopy. It was found that PT insulin has a highly flexible structure in pure water and is pre...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi0108150
更新日期:2001-09-04 00:00:00
abstract::The reaction of cytochrome c oxidase with dioxygen has been studied by means of time-resolved measurements of electrical membrane potential (DeltaPsi). Microsecond time resolution was achieved by starting with the CO-inhibited enzyme, which was photolyzed after addition of oxygen. The time course of the reaction could...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi982275l
更新日期:1999-03-02 00:00:00
abstract::Incubation of 3-(2-phenylethyl)-4-methylsydnone (PMS) with liver microsomes from phenobarbital-pretreated rats or with reconstituted cytochrome P-450b results in loss of the enzyme chromophore. Chromophore loss is NADPH-dependent even though the sydnone decomposes by an oxygen- but not enzyme-dependent process to give...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00413a034
更新日期:1988-06-28 00:00:00
abstract::CP47 is a pigment-protein complex in the core of photosystem II that tranfers excitation energy to the reaction center. Here we report on a spectroscopic investigation of the isolated CP47 complex. By deconvoluting the 77 K absorption and linear dichroism, red-most states at 683 and 690 nm have been identified with os...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi0261948
更新日期:2002-12-24 00:00:00
abstract::The nitrophorins are a family of proteins that use ferric heme to transport nitric oxide (NO) from the salivary glands of blood-sucking insects to their victims, resulting in vasodilation and reduced blood coagulation. We have refined atomic resolution structures of nitrophorin 4 (NP4) from Rhodnius prolixus complexed...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi0109257
更新日期:2001-09-25 00:00:00
abstract::Here we explore the use of ethidium to determine relative affinities of different gene delivery vectors for DNA and describe an improved method for studying the interaction. Specifically, we investigate the binding of poly(amidoamine) dendrimers and show that the DNA-dendrimer-ethidium system is far from thermodynamic...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi1015887
更新日期:2011-02-22 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::A novel liposomal method permits studies of Ca movements across the bilayers of multilamellar vesicles (MLV) which had entrapped the Ca-dependent, fluorescent indicator dye Fura 2. Ionomycin-mediated Ca translocation across MLV of phosphatidylcholine (PC)/dicetyl phosphate (DCP), 9:1, obeyed simple first-order kinetic...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00415a040
更新日期:1988-07-26 00:00:00
abstract::Ultrahigh-resolution X-ray diffraction data from cryo-cooled, B. lentus subtilisin crystals has been collected to a resolution of 0.78 A. The refined model coordinates have a rms deviation of 0.22 A relative to the same structure determined at room temperature and 2.0 A resolution. Several regions of main-chain and si...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi9813983
更新日期:1998-09-29 00:00:00
abstract::The spontaneous hydrolyses of lactic acid O-phenyl phosphate (I) and, to a lesser extent, 3-hydroxybutyric acid O-phenyl phosphate (II) have been investigated and compared with similar intramolecular and bimolecular reactions. Compared to bimolecular nucleophilic reactions, the reactivity of II is similar to other sys...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00682a025
更新日期:1975-06-03 00:00:00
abstract::Catalytic promiscuity is a widespread, but poorly understood, phenomenon among enzymes with particular relevance to the evolution of new functions, drug metabolism, and in vitro biocatalyst engineering. However, there is at present no way to quantitatively measure or compare this important parameter of enzyme function...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi701448p
更新日期:2008-01-08 00:00:00
abstract::There has been intense interest in the development of factor Xa inhibitors for the treatment of thrombotic diseases. Our laboratory has developed a series of novel non-amidine inhibitors of factor Xa. This paper presents two crystal structures of compounds from this series bound to factor Xa. The first structure is de...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi0264061
更新日期:2002-12-31 00:00:00
abstract::During DNA replication, the presence of oligonucleotides with partial homology to the template strand was shown to induce a switch of the polymerase from the normal template to the oligonucleotide. The latter acted as a dead-end template and led to abortive replication. The only prerequisite was that the oligonucleoti...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00028a032
更新日期:1995-07-18 00:00:00
abstract::Human S100B(beta beta) is a small intracellular EF-hand calcium-binding protein that consists of two noncovalently associated 91-residue beta monomers. The three-dimensional structures of S100B reveal the dimer interface consists of four alpha-helices (I, I' and IV, IV') packed in an X-type bundle. In this study, guan...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi0118052
更新日期:2002-03-19 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::The Plasmodium falciparum malarial parasite genome appears to encode one and only one phosphatidylinositol 3'-kinase (PI3K), and sequence analysis suggests that the enzyme is a "class III"- or "Vps34"-type PI3K. PfVps34 has generated excitement as a possible druggable target and potentially a key target of artemisinin...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/acs.biochem.7b00416
更新日期:2017-08-22 00:00:00
abstract::Gelatinase B is a matrix metalloproteinase (MMP-9) involved in tissue remodeling, development, cancer, and inflammation. Neutrophils produce three major forms of (pro)gelatinase B: 92 kDa monomers, homodimers, and complexes of gelatinase B covalently bound to neutrophil gelatinase B-associated lipocalin (NGAL). In con...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi991162e
更新日期:1999-10-19 00:00:00
abstract::In vitro transcription by T7 RNA polymerase was used to prepare 32 different mutations in the 21 nucleotides that participate in the 9 tertiary base pairs or triples of yeast tRNAPhe. The mutations were designed either to disrupt the tertiary interaction or to change the sequence without disrupting the structure by tr...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00462a014
更新日期:1990-03-13 00:00:00
abstract::Isopenicillin N synthase (IPNS) catalyzes the oxidative cyclization of delta-(L-alpha-aminoadipoyl)-L-cysteinyl-D-valine to isopenicillin N. It is proposed that the multiple products produced from certain substrate analogues result from pathway branching after formation of a ferryl oxene intermediate. We have been int...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00022a031
更新日期:1995-06-06 00:00:00
abstract::Neutrophil elastase (NE), a mediator of inflammation, binds with high affinity numerous anionic molecules including suramin, a polysulfated naphthylurea, which inhibits it with a Ki of 0.2 microM and a 4:1 suramin:NE stoichiometry and thus constitutes a potential therapeutic agent. In an attempt to locate the suramin ...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi971029r
更新日期:1997-12-16 00:00:00
abstract::Factor V and factor Va binding to single bilayer phospholipid vesicles was investigated by light-scattering intensity measurements. This technique allows the measurement of free and phospholipid-bound protein concentrations from which equilibrium constants can be obtained. As controls, the Ca2+-dependent phospholipid ...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00587a023
更新日期:1979-10-02 00:00:00
abstract::The antimycotic drug clotrimazole inhibits the function of the gastric H,K-ATPase in a manner similar to that observed for the Na,K-ATPase. Because of the high hydrophobicity of the compound, the interaction between clotrimazole and the ion pump occurs at the membrane domain in the apolar core of the membrane. The enz...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi1004014
更新日期:2010-06-01 00:00:00
abstract::The processes of liposome solubilization and reconstitution were studied by using n-dodecyl octaethylene glycol monoether (C12E8). The solubilization of large unilamellar liposomes prepared by reverse-phase evaporation was systematically investigated by turbidity, 31P nuclear magnetic resonance, and centrifugation exp...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00492a022
更新日期:1990-10-09 00:00:00
abstract::The effects of cysteine modification and variations in pH on the equilibrium parameters for inducer and operator binding to the lactose repressor protein were examined. Operator binding affinity was minimally affected by increasing the pH from 7.5 to 9.2, whereas inducer binding was decreased for both the unliganded p...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00367a020
更新日期:1986-09-23 00:00:00
abstract::We have examined the reduction of cyanide by using the purified component proteins of nitrogenase (Av1 and Av2). The previously reported self-inhibition phenomenon was found to be an artifact. One of the two species present in cyanide solutions, CN-, was shown to be a potent reversible inhibitor (Ki = 27 microM) of to...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00261a031
更新日期:1982-08-31 00:00:00
abstract::The preferential in vitro methylation of histone H3 by coactivator-associated arginine methyltransferase 1 (CARM1) has been proposed as a basis for its ability to enhance gene transcription [Chen, D., et al. (1999) Science 284, 2174-2177]. To further evaluate the significance of H3 methylation, we studied the kinetics...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi002631b
更新日期:2001-05-15 00:00:00
abstract::We have studied the pathway and kinetics of refolding of recombinant human brain-derived neurotrophic factor (BDNF), which is a very tightly-associated dimer in its native state. When BDNF unfolded in 6 M guanidine hydrochloride is diluted 20-fold into phosphate-buffered saline, a partially folded intermediate is rapi...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00091a036
更新日期:1993-10-12 00:00:00
abstract::Electron-transfer reactions following the formation of P700(+)A1- have been studied in isolated Photosystem I complexes from Synechococcus elongatus between 300 and 5 K by flash absorption spectroscopy. (1) In the range from 300 to 200 K, A1- is reoxidized by electron transfer to the iron-sulfur cluster FX. The rate s...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi973182r
更新日期:1998-06-30 00:00:00
abstract::In Sphingomonas CHY-1, a single ring-hydroxylating dioxygenase is responsible for the initial attack of a range of polycyclic aromatic hydrocarbons (PAHs) composed of up to five rings. The components of this enzyme were separately purified and characterized. The oxygenase component (ht-PhnI) was shown to contain one R...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi0611311
更新日期:2006-10-10 00:00:00
abstract::The role of interleukin-8 (IL-8) and related CXC chemokines has been demonstrated in many human diseases. However, more profound studies, e.g., by blocking the effect of these inflammatory mediators, request animal models and hence the identification of all human counterparts for commonly used laboratory animals. In t...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi0011227
更新日期:2000-11-28 00:00:00