Abstract:
:The Escherichia coli cAMP receptor protein (CRP) displays biphasic characteristics in protease and beta-galactosidase induction assays at increasing cAMP concentrations in response to ligand binding at the secondary binding site located between the primary binding site and the DNA binding domain. Two mutants were created to determine the mechanistic reason for the CRP biphasic response by inhibiting binding of cAMP to the secondary site via interference with the Arg 181 interaction with the ligand's phosphate. The S179A/R180D/E181H mutant binds two cAMP molecules per dimer, does not exhibit a biphasic response, lacks selective DNA binding, and has inhibited nonselective DNA binding. The R180K mutant binds four cAMP molecules per dimer, exhibits a biphasic response, nonselective DNA binding similar to CRP, but has inhibited selective DNA binding characteristics. The results are consistent with a 2 x 2-binding site scheme were both primary binding sites must be occupied before the secondary binding sites are occupied. A structural mechanism suggesting the secondary sites are formed by binding of cAMP to the primary sites is proposed. AMMP-generated molecular models suggest that R180 orients E181 to produce selective DNA binding, Arg 169 interactions are necessary for nonselective DNA binding, and the position of Leu 57 inhibits chymotrypsin cleavage of Phe 136. DNA binding results suggest that CRP may be the unknown transcription factor which binds to the temperature sensitive dsrA promoter.
journal_name
Biochemistryjournal_title
Biochemistryauthors
Scott SP,Jarjous Sdoi
10.1021/bi0479609subject
Has Abstractpub_date
2005-06-21 00:00:00pages
8730-48issue
24eissn
0006-2960issn
1520-4995journal_volume
44pub_type
杂志文章相关文献
BIOCHEMISTRY文献大全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::The covalent modification of chicken liver fatty acid synthase by 4-(1-pyrenyl)butyryl-CoA (PBA-CoA), a fluorescent analogue of acetyl- and malonyl-CoA, has been studied. The binding isotherms and the kinetics of inactivation suggest 2 mol of PBA-CoA/mol of enzyme is specifically incorporated into the enzyme. Two clas...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00281a032
更新日期:1983-06-07 00:00:00
abstract::Human apolipoprotein stimulation of sphingomyelin (SM) hydrolysis by sphingomyelinase from human skin fibroblasts has been studied. Apolipoproteins A-I, A-II, B, C-I, and E do not enhance sphingomyelin hydrolysis above control levels. In contrast, apoC-II stimulates sphingomyelin hydrolysis by approximately 2.5-fold. ...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00363a036
更新日期:1986-07-29 00:00:00
abstract::The synthesis is described of four new cleavable, photosensitive, heterobifunctional cross-linking reagents for use in examining membrane organization: 4'-azidoazobenzene-4oxysuccinimide ester (1), N-[4-(p-azidophenylazo)benzoyl]-3-aminopropyl-N'-oxysuccinimide ester (2), N-[4-(p-azidophenylazo)benzoyl]-6-aminohexyl-N...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00560a007
更新日期:1980-09-16 00:00:00
abstract::Fluorescence recovery after photobleaching was used to measure the diffusion coefficient of green fluorescent protein (GFP, 27 kDa) in Escherichia coli in the presence or absence of four coexpressed proteins: cytoplasmic maltose binding protein (42 kDa), tau-40 (45 kDa), alpha-synuclein (14 kDa), or calmodulin (17 kDa...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi9004107
更新日期:2009-06-16 00:00:00
abstract::Kinetics of reduction of phototrophic bacterial flavocytochromes c by exogenous flavin semiquinones and fully reduced flavins generated by laser flash photolysis have been studied. The mechanisms of reduction of Chromatium and Chlorobium flavocytochromes c are more similar to one another than previously thought. Neith...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00327a002
更新日期:1985-03-12 00:00:00
abstract::Most proteins are denatured by heat treatment, and the process is usually irreversible. However, some proteins, such as hyperthermophilic proteins are known to be stable even at the boiling temperature of water. We here describe a systematic investigation of thermal behavior of proteins by purifying and characterizing...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi001441y
更新日期:2000-12-05 00:00:00
abstract::Escherichia coli dihydrofolate reductase contains five tryptophan residues that are spatially distributed throughout the protein and located in different secondary structural elements. When these tryptophans are replaced with [6-19F]tryptophan, distinct native and unfolded resonances can be resolved in the 1-D 19F NMR...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi971962u
更新日期:1998-01-06 00:00:00
abstract::The steroidogenic acute regulatory protein (StAR) facilitates the movement of cholesterol from the outer to inner mitochondrial membrane in adrenal and gonadal cells, fostering steroid biosynthesis. MLN64 is a 445-amino acid protein of unknown function. When 218 amino-terminal residues of MLN-64 are deleted, the resul...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi000911l
更新日期:2000-09-26 00:00:00
abstract::Hormone-sensitive lipase (HSL) is a rate-limiting enzyme in lipolysis that displays broad substrate specificity. HSL function is regulated by reversible phosphorylation that occurs within a 150 aa "regulatory module" of the protein. The current studies used mutational analysis to dissect the contribution of the "regul...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi049206t
更新日期:2005-02-15 00:00:00
abstract::A novel truncated form (residues 1-214, with a randomized C-terminal tail) of the ligand-binding extracellular domain (ECD) of the human alpha1 glycine receptor (GlyR), with amino acids from the corresponding sequence of an acetylcholine binding protein (AChBP) substituted for two relatively hydrophobic membrane-proxi...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi800659x
更新日期:2008-09-16 00:00:00
abstract::We have purified and characterized a novel 30-kDa glycoprotein (gp30) with TGF alpha-like properties secreted from the estrogen receptor negative breast cancer cell line MDA-MB-231. This factor was immunoprecipitated by an anti-TGF alpha polyclonal antibody and also had TGF alpha-like biological activity, as assayed b...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00147a018
更新日期:1992-08-18 00:00:00
abstract::The DNA of Novikoff hepatoma ascites cells was found to contain a 3.6-megadalton EcoRI restriction fragment, referred to as EcoRI fragment A (Parker et al., 1979). C0t analyses demonstrated an enrichment of fragment A sequences in Novikoff hepatoma genome relative to normal rat liver DNA. This fragment was cloned in l...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00507a017
更新日期:1981-02-17 00:00:00
abstract::The nuclear transport of the chromatin remodeling protein nucleoplasmin and chromatin building histones is mediated by importins. Nucleoplasmin (NP) contains a classical bipartite nuclear localization signal (NLS) that is recognized by the importin α/β heterodimer, while histones present multiple NLS-like motifs that ...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi2008867
更新日期:2011-08-23 00:00:00
abstract::The rate of depolymerization of microtubules upon lowering the temperature was found to depend on the amount of time elapsed since the beginning of the assembly process. In the first minutes following self-assembly at 37 degrees C, microtubules are more cold sensitive and depolymerize faster than later at the steady s...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00534a039
更新日期:1982-03-02 00:00:00
abstract::Human melanin-concentrating hormone (hMCH) and many of its analogues are potent but nonspecific ligands for human melanin-concentrating hormone receptors 1 and 2 (hMCH-1R and hMCH-2R). To differentiate between the physiological functions of these receptors, selective antagonists are needed. In this study, analogues of...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi0200514
更新日期:2002-05-21 00:00:00
abstract::125I-Labeled enterotoxin from Clostridium perfringens was utilized to characterize the association of the enterotoxin with cells isolated from rabbit intestine and tissue homogenates from liver, kidney, and brain. The enterotoxin was found to bind in a specific and saturable manner to cells from intestine and to tissu...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00562a014
更新日期:1980-10-14 00:00:00
abstract::The essential active site Fe3+ of protocatechuate 3,4-dioxygenase [3, 4-PCD, subunit structure (alphabetaFe3+)12] is bound by axial ligands, Tyr447 (147beta) and His462 (162beta), and equatorial ligands, Tyr408 (108beta), His460 (160beta), and a solvent OH- (Wat827). Recent X-ray crystallographic studies have shown th...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi972047b
更新日期:1998-02-24 00:00:00
abstract::We report nuclear magnetic resonance (NMR) data indicating that the Rieske protein from the cytochrome bc complex of Thermus thermophilus (TtRp) undergoes modest redox-state-dependent and ligand-dependent conformational changes. To test models concerning the mechanism by which TtRp transfers between different sites on...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi400296c
更新日期:2013-04-30 00:00:00
abstract::Homing endonucleases are distinguished by their ability to catalyze the cleavage of double-stranded DNA with extremely high specificity. I-PpoI endonuclease, a homing endonuclease from the slime mold Physarum polycephalum, is a small enzyme (2 x 20 kDa) of known three-dimensional structure that catalyzes the cleavage ...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi991452v
更新日期:1999-12-07 00:00:00
abstract::Proelastase has been purified to homogeneity from rat pancreatic tissue by a combination of CM-Sephadex and immobilized protease inhibitor affinity resins. Trypsin activation yields an elastolytic enzyme that possesses a specificity toward small hydrophobic residues in synthetic amide substrates, similar to those of p...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00285a008
更新日期:1983-08-02 00:00:00
abstract::While within a human host the opportunistic pathogen Toxoplasma gondii relies heavily on glycolysis for its energy needs. Lactate dehydrogenase (LDH), the terminal enzyme in anaerobic glycolysis necessary for NAD(+) regeneration, therefore represents an attractive therapeutic target. The tachyzoite stage lactate dehyd...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi035108g
更新日期:2004-02-03 00:00:00
abstract::The hinge domain encompasses amino acids 51-60 of lactose repressor (LacI) and plays an important role in its regulatory interaction with operator DNA. This segment makes both hinge-DNA and hinge-hinge' contacts that are critical to DNA binding. Furthermore, this small region serves as a central element in communicati...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi0114067
更新日期:2001-12-25 00:00:00
abstract::The complete amino acid sequence of the major component myoglobin from the dwarf sperm whale, Kogia simus, was determined by specific cleavage of the protein to obtain large peptides which are readily degraded by the automatic sequenator. Three easily separable peptides were obtained by cleaving the protein at its two...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00624a010
更新日期:1977-03-08 00:00:00
abstract::Two distinct regions of angiogenin are critical for angiogenic activity: a catalytic site capable of cleaving RNA and a noncatalytic site, encompassing residues 60-68, which may bind to an endothelial cell-surface receptor [Hallahan, T. W., Shapiro, R., & Vallee, B. L. (1991) Proc. Natl. Acad. Sci. U.S.A. 88, 2222-222...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00149a036
更新日期:1992-09-01 00:00:00
abstract::Retinoid X receptors (RXRs) are transcription factors with important functions in embryonic development, metabolic processes, differentiation, and apoptosis. A particular feature of RXRs is their ability to act as obligatory heterodimerization partners of class II nuclear receptors. At the same time, these receptors a...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/acs.biochem.5b01122
更新日期:2016-03-29 00:00:00
abstract::Proton and phosphorus-31 nuclear magnetic resonance (1H and 31P NMR) studies of the interaction between a tridecapeptide pheromone, the alpha-factor of Saccharomyces cerevisiae, and sonicated lipid vesicles are reported. 31P NMR studies demonstrate that there is interaction of the peptide with the phosphorus headgroup...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00436a017
更新日期:1989-05-16 00:00:00
abstract::The carbohydrate binding specificity of the seed lectin from Artocarpus integrifolia, artocarpin, has been elucidated by the enzyme-linked lectin absorbent assay [Misquith, S., et al (1994) J. Biol. Chem. 269, 30393-30401], wherein it was demonstrated to be a Man/Glc specific lectin with high affinity for the trisacch...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi000744p
更新日期:2000-09-05 00:00:00
abstract::Insulin and insulin-like growth factor 1 (IGF-1) share high sequence homology, but their folding behaviors are significantly different: insulin folds into one unique thermodynamically controlled structure, while IGF-1 folds into two thermodynamically controlled disulfide isomers. However, the origin of their different...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi0346289
更新日期:2003-08-19 00:00:00
abstract::Blastochloris tepida is a newly described thermophilic purple bacterium containing bacteriochlorophyll b. Using purified light-harvesting 1 reaction center (LH1-RC) core complexes from Blc. tepida, we compared the biochemical, spectroscopic, and thermal denaturation properties of these complexes with those of its meso...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/acs.biochem.0c00192
更新日期:2020-06-30 00:00:00