Abstract：
:We have previously shown that the anticodon of methionine tRNAs contains most, if not all, of the nucleotides required for specific recognition of tRNA substrates by Escherichia coli methionyl-tRNA synthetase [Schulman, L. H., & Pelka, H. (1988) Science 242, 765-768]. Previous cross-linking experiments have also identified a site in the synthetase that lies within 14 A of the anticodon binding domain [Leon, O., & Schulman, L. H. (1987) Biochemistry 26, 5416-5422]. In the present work, we have carried out site-directed mutagenesis of this domain, creating conservative amino acid changes at residues that contain side chains having potential hydrogen-bond donors or acceptors. Only one of these changes, converting Trp461----Phe, had a significant effect on aminoacylation. The mutant enzyme showed an approximately 60-100-fold increase in Km for methionine tRNAs, with little or no change in the Km for methionine or ATP or in the maximal velocity of the aminoacylation reaction. Conversion of the adjacent Pro460 to Leu resulted in a smaller increase in Km for tRNA(Mets), with no change in the other kinetic parameters. Examination of the interaction of the mutant enzymes with a series of tRNA(Met) derivatives containing base substitutions in the anticodon revealed sequence-specific interactions between the Phe461 mutant and different anticodons. Km values were highest for tRNA(mMet) derivatives containing the normal anticodon wobble base C. Base substitutions at this site decreased the Km for aminoacylation by the Phe461 mutant, while increasing the Km for the wild-type enzyme and for the Leu460 mutant to values greater than 100 microM.(ABSTRACT TRUNCATED AT 250 WORDS)
journal_name
Biochemistryjournal_title
Biochemistryauthors
Ghosh G,Pelka H,Schulman LHdoi
10.1021/bi00461a003subject
Has Abstractpub_date
1990-03-06 00:00:00pages
2220-5issue
9eissn
0006-2960issn
1520-4995journal_volume
29pub_type
杂志文章相关文献
BIOCHEMISTRY文献大全abstract：:Calmodulin (CaM) is an essential, eukaryotic protein comprised of two highly homologous domains (N and C). CaM binds four calcium ions cooperatively, regulating a wide array of target proteins. A genetic screen of Paramecia by Kung [Kung, C. et al. (1992) Cell Calcium 13, 413-425] demonstrated that the domains of CaM ...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi061134d
更新日期：2006-12-05 00:00:00
abstract：:kappa-Bungarotoxin (kappa-bgt) is a 66-residue peptide originally purified from snake venom that acts as an antagonist at certain acetylcholine receptors. It is one of four homologous kappa-neurotoxins that are distinguished from the structurally related alpha-neurotoxins by their ability to block the alpha 3-subunit-...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi00248a004
更新日期：1994-11-08 00:00:00
abstract：:The protein composition, steady state and time-resolved fluorescence emission spectra were studied in solubilized and aggregated LHCII complexes, that were prepared according to two different isolation protocols: (1) by fractionation of cation-depleted thylakoid membranes using the non-ionic detergent Triton X-100 acc...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi9625253
更新日期：1997-06-17 00:00:00
abstract：:To better understand the mechanism of nitric oxide (NO) synthesis, we studied conversion of N-hydroxy-L-arginine (NOHA) or L-arginine (Arg) to citrulline and NO under single-turnover conditions using the oxygenase domain of neuronal nitric oxide synthase (nNOSoxy) and rapid scanning stopped-flow spectroscopy. When ana...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi9920228
更新日期：2000-03-07 00:00:00
abstract：:The ability of DNA topoisomerase I to mediate the formation of structurally modified DNA duplexes was studied utilizing suicide substrates containing high-efficiency cleavage sites and acceptor oligonucleotides in which the 5'-terminal nucleotides were varied. When the substrates were nicked duplexes, the divalent cat...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi972707c
更新日期：1998-02-24 00:00:00
abstract：:Glucocorticoid (GC) hormones induce apoptosis in T-cell and pre-B-cell acute lymphoblastic leukemia (ALL) cells. Steroid-mediated apoptosis requires a threshold level of the glucocorticoid receptor (GR) protein, and increasing the intracellular GR levels in ALL cells would augment their hormone sensitivity. A protein ...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi1007723
更新日期：2010-10-19 00:00:00
abstract：:The nature of the active site cofactor and the amino acid sequence flanking this structure have been determined in a range of copper amine oxidases. For enzymes from porcine plasma, porcine kidney, and pea seedlings, proteolytic digestion was performed on phenylhydrazone or p-nitrophenylhydrazone derivatives. Thermoly...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi00163a025
更新日期：1992-12-08 00:00:00
abstract：:Chloroperoxidase is a versatile fungal heme-thiolate protein that catalyzes a variety of one-electron and two-electron oxidations. We report here that the alkylation of an essential histidine residue showed no effect on the one-electron peroxidations but inhibited two-electron oxidations. The pH profiles of different ...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi7022656
更新日期：2008-03-04 00:00:00
abstract：:The aminolysis of the depsipeptide m-[[(phenylacetyl)glycyl]oxy]benzoic acid (1) by D-phenylalanine, catalyzed by the beta-lactamase of Enterobacter cloacae P99, is inhibited by the product of the reaction, (phenylacetyl)glycyl-D-phenylalanine (2), by the peptide analogue of 1, m-[(phenylacetyl)-glycinamido]benzoic ac...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi00443a015
更新日期：1989-08-22 00:00:00
abstract：:Nitric oxide (NO) regulates cardiovascular hemostasis by binding to soluble guanylyl cyclase (sGC), leading to cGMP production, reduced cytosolic calcium concentration ([Ca(2+)](i)), and vasorelaxation. Thrombospondin-1 (TSP-1), a secreted matricellular protein, was recently discovered to inhibit NO signaling and sGC ...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi201060c
更新日期：2011-09-13 00:00:00
abstract：:Cyclopentenone prostanoids (cyP) arise as important modulators of inflammation and cell proliferation. Although their physiological significance has not been fully elucidated, their potent biological effects have spurred their study as leads for the development of therapeutic agents. A key determinant of cyP action is...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi602389p
更新日期：2007-06-05 00:00:00
abstract：:Electronic absorption, EPR, and resonance Raman spectroscopies revealed that CooA, the CO-sensing transcriptional regulator from Rhodospirillum rubrum, reacts with NO to form a five-coordinate NO-heme. NO must therefore displace both of the heme ligands from six-coordinate, low-spin Fe(II)CooA in forming five-coordina...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi991378g
更新日期：2000-01-18 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：:Ceruloplasmin is unique among the multicopper oxidases in that in addition to the usual copper stoichiometry of one Type 1 copper site and a Type 2/Type 3 trinuclear copper cluster, it contains two other Type 1 sites. This assignment of copper sites, based on copper quantitation, sequence alignment, and crystallograph...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi980434v
更新日期：1998-06-30 00:00:00
abstract：:Nicotinic acid phosphoribosyltransferase (NAPRTase; EC 2.4.2.11) forms nicotinic acid mononucleotide (NAMN) and PPi from 5-phosphoribosyl 1-pyrophosphate (PRPP) and nicotinic acid (NA). The Vmax NAMN synthesis activity of the Salmonella typhimurium enzyme is stimulated about 10-fold by ATP, which, when present, is hyd...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi9720134
更新日期：1998-03-24 00:00:00
abstract：:A conformational transition is described for the polypeptide, gramicidin A, in which a dimer that forms a left-handed intertwined antiparallel helix is converted to a single-stranded amino terminus to amino terminus right-handed helix. The starting structure is determined here by solution NMR methods while reference i...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi00152a019
更新日期：1992-09-22 00:00:00
abstract：:Methyl-coenzyme M reductase (MCR) catalyzes the methane-forming step in methanogenic archaea. The active enzyme harbors the nickel(I) hydrocorphin coenzyme F-430 as a prosthetic group and catalyzes the reversible reduction of methyl-coenzyme M (CH3-S-CoM) with coenzyme B (HS-CoM) to methane and CoM-S-S-CoB. MCR is als...
journal_title：Biochemistry
pub_type： 杂志文章,评审
doi：10.1021/acs.biochem.9b00164
更新日期：2019-12-31 00:00:00
abstract：:His216 is a well-conserved residue in pyruvate carboxylases and, on the basis of structures of the enzyme, appears to have a role in the binding of MgATP, forming an interaction with the 3'-hydroxyl group of the ribose ring. Mutation of this residue to asparagine results in a 9-fold increase in the Km for MgATP in its...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi4016814
更新日期：2014-02-18 00:00:00
abstract：:The Escherichia coli D-galactose and D-glucose receptor possesses a Ca(II)-binding site closely related in structure and metal-binding characteristics to the eukaryotic EF-hand sites. Only the structure of the Ca(II)-occupied site is known. To investigate the structural change triggered by Ca(II) and Sr(II) binding, w...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi00231a022
更新日期：1991-04-30 00:00:00
abstract：:We have used 2D 1H NMR to determine the structure of glucagon-like peptide-1-(7-36) amide bound to a dodecylphosphocholine micelle. In this membranelike environment, the peptide hormone is shown to have a structure similar to that observed for glucagon. It consists of an N-terminal random coil segment (residues 1-7), ...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi00178a009
更新日期：1994-03-29 00:00:00
abstract：:The interaction of nile red (NR) with apomyoglobin (ApoMb) in the native (pH 7) and molten globule (pH 4) states was investigated using experimental and computational methods. NR binds to hydrophobic locations in ApoMb with higher affinity (K(d) = 25 +/- 5 microM) in the native state than in the molten globule state (...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi051905y
更新日期：2006-04-25 00:00:00
abstract：:It has been suggested that the mechanism of alkaline phosphatase (AP) is associative, or triester-like, because phosphorothioate monoesters are hydrolyzed by AP approximately 10(2)-fold slower than phosphate monoesters. This "thio effect" is similar to that observed for the nonenzymatic hydrolysis of phosphate trieste...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi000899x
更新日期：2000-08-08 00:00:00
abstract：:The positions of single amino acids in the interhelical loop regions and the C-terminal tail of bacteriorhodopsin (bR) were investigated by X-ray diffraction using site-directed heavy-atom labeling. Since wild-type bR does not contain any cysteines, appropriate cysteine mutants were produced with a unique sulfhydryl g...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi971735s
更新日期：1998-07-21 00:00:00
abstract：:We have examined the ability of the Escherichia coli single-stranded DNA binding protein (SSB) tetramer to form its different binding modes on poly(dC), poly(U), and poly(A) over a range of NaCl and NaF concentrations for comparison with previous studies with poly(dT). In reverse titrations with poly(U) and poly(A) at...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi00186a016
更新日期：1994-05-24 00:00:00
abstract：:Exons 1 and 2 and exon 8 of the mu class GSH transferases from rat encode sequence-variable regions 1 and 4 of mu class isoenzymes, respectively. These two of four variable regions are located at the N- and C-termini of this isoenzyme class and impinge on the active site. In order to assess the influence of these vari...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi00157a005
更新日期：1992-10-27 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：:The interaction of the zinc finger protein WT1 with RNA aptamers has been investigated using a quantitative binding assay, and the results have been compared to those from a previous study of the DNA binding properties of this protein. A recombinant peptide containing the four zinc fingers of WT1 (WT1-ZFP) binds to re...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi001941r
更新日期：2001-02-20 00:00:00
abstract：:The complete amino acid sequences of two basic proline-rich proteins, IB-1 and IB-6, from human parotid saliva have been determined. Fragments for sequence analysis were obtained by enzymatic digestions. The proteins have molecular weights of 9571 (IB-1) and 11,530 (IB-6) and contain 34 and 39 mol % proline, respectiv...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi00357a013
更新日期：1986-05-06 00:00:00
abstract：:Six affinity reagents containing chemically reactive groups, either on the phosphate residue at the 5'-end or on the 5'- or 3'-end internucleoside phosphate linkages of the oligothymidylate primers, were used to covalently modify the human immunodeficiency virus type 1 reverse transcriptase (HIV-1 RT). After covalent ...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi00065a015
更新日期：1993-04-13 00:00:00
abstract：:DNA transaction reactions require formation of nucleoprotein complexes that involve multifaceted DNA-protein and protein-protein interactions. Genetic and biochemical studies suggested that the higher order Gal repressosome structure, which governs the transcription of two tandem galpromoters in Escherichia coli, invo...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi047720t
更新日期：2005-04-12 00:00:00
