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Query: UNIPROT:P06889 (
Mol
)
630,302
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
The DNA-binding domain of the single-stranded DNA-binding protein IKe GVP was studied by means of 1H nuclear magnetic resonance, through use of oligonucleotides of two and three adenyl residues in length, that were spin-labelled at their 3' and/or 5' termini. These spin-labelled ligands were found to cause line broadening of specific protein resonances when bound to the protein, although they were present in small quantities, i.e. of the order of 0.04 molar equivalent and less. The line broadening of protein resonances was made manifest by means of difference one and two-dimensional spectroscopy. Difference one-dimensional experiments revealed line broadening of the same protein resonances upon binding of either 3' or 5' spin-labelled oligonucleotides. Evidence in favour of the existence of a fixed 5' to 3' orientation in the binding of oligonucleotides to the protein surface was therefore not obtained from the spin-labelled oligonucleotide binding studies. Residue-specific assignments of broadened resonances could not, or could only sparsely, be derived from the difference one-dimensional spectra, because of the tremendous overlap in the aliphatic region of the spectrum. In contrast, such assignments were easily obtained from the difference two-dimensional spectra, which were recorded by means of both total correlated spectroscopy and nuclear Overhauser effect spectroscopy. Difference signals were detected for 15 spin systems; ten out of these were assigned to the residues I29, Y27, S20, G18, R16, T28, K22, Q21, V19 and S17 in the amino acid sequence of IKe GVP; the other five spin systems could be assigned to a phenylalanyl residue, an arginyl or lysyl residue, an
aspartic acid
or asparagyl residue, a glycyl residue and a glutamic acid or glutamyl residue. From the evaluation of the relative difference signals, it was concluded that the direct surroundings of the spin-label group of the labelled oligonucleotide in the bound state is composed of the first five residues in the former group of residues and the five residues in the latter group.(ABSTRACT TRUNCATED AT 400 WORDS)
J
Mol
Biol 1989 Mar 05
PMID:Two-dimensional 1H nuclear magnetic resonance studies on the gene V-encoded single-stranded DNA-binding protein of the filamentous bacteriophage IKe. II. Characterization of the DNA-binding wing with the aid of spin-labelled oligonucleotides. 270 38
Chromatographically purified fractions of aqueous-ethanolic extracts from Baptisia tinctoria roots contained a strong lymphocyte DNA synthesis-stimulating activity. Electrophoretic analysis of these fractions revealed four distinct protein bands with molecular masses of P1 = 58 kD; P4 = 31 kD; P5 = 26 kD; and P6 = 14 kD. They contained carbohydrate as determined by periodic acid Schiff staining. An estimation of the approximate amount of sugar was done by using human transferrin as a reference, this method revealed the following values: P1 = 27%; P4 = 12%; P5 = 14%; and P6 = 8%. The mixture of proteins and every single band were immunoreactive with a polyclonal antiserum against Baptisia proteins determined in immune and dot blots, respectively. Electrophoretically purified proteins were characterized by tryptic cleavage and determination of their amino acid content. They contained several common amino acids, predominantly
aspartic acid
, glutamic acid, threonine, and alanine. The content of glucosamine and/or galactosamine was less than 0.2
Mol
-per cent. The four proteins revealed pI values between 5.3 and 4.7. Protein P 4 was immunochemically related to phytohemagglutinin but, in contrast to PHA-P, it exhibited no hemagglutinating activity and no leucagglutinating activity like PHA-L.
...
PMID:[Immunologically active glycoproteins of Baptisia tinctoria]. 281 70
We have determined the nucleotide sequence changes caused by three missense mutations leading to the production of inactive colicin E3 proteins. The ceaC1 mutation, affecting the translocation of colicin E3 through bacterial membranes, is caused by a serine to phenylalanine change at position 37 within the glycine-rich region at the N-terminal part of colicin E3. This confirms previous results suggesting a role for this domain in colicin uptake by sensitive cells. The ceaC2 and ceaC3 mutations, abolishing colicin E3 RNase activity, affect the C-terminal enzymatic domain of the molecule. In the ceaC2 mutant, serine at position 529 was converted to leucine. The ceaC3 mutation replaced a glycine residue at position 524 with an
aspartic acid
residue. The two mutations ceaC2 and ceaC3 yield information on the amino acid residues involved in the RNase activity of colicin E3.
Mol
Microbiol 1987 Jul
PMID:DNA sequence analysis of three missense mutations affecting colicin E3 bactericidal activity. 283 30
A library of recombinant bacteriophage was prepared from ts167 avian erythroblastosis virus-transformed erythroid precursor cells (HD6), and integrated proviruses from three distinct genomic loci were isolated. A subclone of one of these proviruses (pAEV1) was shown to confer temperature-sensitive release from transformation of erythroid precursor cells in vitro. The predicted amino acid sequence of the v-erbB polypeptide from the mutant had a single amino acid change when compared with the wild-type parental virus. When the wild-type amino acid was introduced into the temperature-sensitive avian erythroblastosis virus provirus in pAEV1, all erythroid clones produced in vitro were phenotypically wild type. The mutation is a change from a histidine to an
aspartic acid
in the temperature-sensitive v-erbB polypeptide. It is located in the center of the tyrosine-specific protein kinase domain and corresponds to amino acid position 826 of the human epidermal growth factor receptor sequence.
Mol
Cell Biol 1986 May
PMID:A single amino acid substitution in v-erbB confers a thermolabile phenotype to ts167 avian erythroblastosis virus-transformed erythroid cells. 287 64
During senescence in the filamentous fungus Podospora anserina, specific regions of the mitochondrial genome, termed senDNA are excised, ligated and amplified. We have cloned in their entirety three such autonomously replicating plasmids, alpha, beta and epsilon senDNA. None of these plasmids displayed cross-hybridization nor did we detect any significant DNA homology by computer analysis. The complete DNA sequence of the 2.5 kb alpha, the 5.5 kb epsilon and about 3.4 kb of the 9.8 kb beta senDNA is presented (kb = 10(3) base-pairs). These sequences were analyzed for the presence of consensus sequences common to introns, and it was found that alpha senDNA has the characteristics of a group II intron, epsilon senDNA contains three group I introns, and beta senDNA did not show relevant sequences in the 3.4 kb examined. Comparison of the 5' and 3'-flanking sequences of alpha senDNA with oxi 3 (Co I) amino acid sequences from Neurospora crassa and Saccharomyces cerevisiae revealed significant homology and provided strong support that the excised alpha senDNA itself consists entirely of an intron. Upstream from the oxi 3 gene a transfer RNA cysteine sequence was detected. beta senDNA contained four tRNA sequences,
aspartic acid
, serine, valine and tryptophan, and sequences homologous to URFC (untranslated reading frame C) as well as two new URFs. epsilon senDNA contained sequences homologous to ATPase 8 and URFl; URFl was interrupted by three group I introns. The excision site sequences, as located by S1 nuclease mapping were unique for each senDNA. Analysis for repeated units showed that each plasmid contained elements which could be involved in secondary structure required for the alignment of distal ends preparatory to excision. These results are interpreted in terms of the structural requirements of mobile elements including the possible involvement of reverse transcriptase in the excision-ligation-amplification process.
J
Mol
Biol 1985 Oct 20
PMID:Excision-amplification of mitochondrial DNA during senescence in Podospora anserina. DNA sequence analysis of three unique "plasmids". 299 55
DNA fragments of 3.4 kb containing the gyrB gene were cloned from Escherichia coli KL-16 and from spontaneous nalidixic acid-resistant mutants. The mutations (nal-24 and nal-31) had been determined to be in the gyrB gene by transduction analysis. Nucleotide sequence analysis of the cloned DNA fragments revealed that nal-24 was a G to A transition at the first base of the 426th codon of the gyrB gene, resulting in an amino acid change from
aspartic acid
to asparagine, and nal-31 was an A to G transition at the first base of the 447th codon, resulting in an amino acid change from lysine to glutamic acid. This indicates tha mutations in the gyrB gene are responsible for nalidixic acid resistance.
Mol
Gen Genet 1986 Sep
PMID:Nalidixic acid-resistant mutations of the gyrB gene of Escherichia coli. 302 Mar 76
Mammalian ribonucleotide reductase is regulated by the binding of dATP and other nucleotide effectors to allosteric sites on subunit M1. Using mRNA from a mutant mouse T-lymphoma (S49) cell line, we have isolated a cDNA which encodes an altered, dATP feedback-resistant subunit M1. The mutant cDNA contains a single point mutation (a G-to-A transition) at codon 57, converting
aspartic acid
to asparagine. Proof that this mutation is responsible for the phenotype of dATP feedback resistance is provided by the following evidence. (i) The mutation was detected only in mutant S49 cells containing dATP feedback-resistant ribonucleotide reductase and not in wild-type or other mutant S49 cells. (ii) Transfection of Chinese hamster ovary cells with an expression plasmid containing the mutant M1 cDNA resulted in the production of dATP feedback-resistant ribonucleotide reductase. Transfected CHO cells expressing the mutant M1 cDNA exhibited a 15- to 25-fold increase in the frequency of spontaneous mutation to 6-thioguanine resistance, confirming that dATP feedback-resistant ribonucleotide reductase produces a mutator phenotype in mammalian cells. The availability of a cDNA which encodes dATP feedback-resistant subunit M1 thus provides a means of manipulating by transfection the frequency of spontaneous mutation in mammalian cells.
Mol
Cell Biol 1988 Jul
PMID:Molecular cloning of the cDNA for a mutant mouse ribonucleotide reductase M1 that produces a dominant mutator phenotype in mammalian cells. 304 91
DNA including the coding sequence for the A chain of the mutant diphtheria toxin tox 176 was cloned. The cloned mature A-chain coding sequence showed a G-to-A transition at nucleotide 383 as the only difference from the wild-type sequence. This resulted in replacement of the glycine at position 128 by
aspartic acid
in the predicted amino acid sequence. A eucaryotic cell expression plasmid, pTH1-176, was constructed in which the tox 176 A-chain coding sequence was attached to a truncated metallothionein promoter. The toxicity of this construct, compared with that of the corresponding wild-type diphtheria toxin A-chain plasmid, pTH1, was assessed after transfection into the human 293 cell line by an indirect transient expression assay (I. H. Maxwell, F. Maxwell, and L. M. Glode, Cancer Res. 46:4660-4664, 1986). For the same effect, 15- to 30-fold more pTH1-176 than pTH1 was required, a result consistent with previous in vitro estimates of the diminished activity of the tox 176 A chain. Controlled expression of the cloned tox 176 A-chain coding sequence may provide a means of eliminating specific cell populations in an organism, for which purpose the wild-type diphtheria toxin A chain might prove too toxic.
Mol
Cell Biol 1987 Apr
PMID:Cloning, sequence determination, and expression in transfected cells of the coding sequence for the tox 176 attenuated diphtheria toxin A chain. 311 May 96
A monoclonal anti-idiotype (M3.9) raised against the covalently linked Mcg lambda chain dimer binds with a similar affinity to the Mcg IgG immunoglobulin and covalent heterodimers of Mcg with other human L chains. Despite having identical amino acid sequences, the two light chains in the Mcg dimer adopt different conformations with monomer 1 acting as a heavy chain analog and monomer 2 behaving like a light chain component of an Fab. As the lambda chain in the Mcg IgG and at least one hybrid L chain dimer (Mcg X Weir) assumes a conformation similar to that of monomer 2 and the binding of anti-idiotype requires only the presence of a single Mcg lambda chain, we conclude that the idiotope is restricted to the monomer 2 type of the Mcg lambda chain conformational isomer. Cooperative binding of two molecules of rhodamine 123 in the main cavity of the Mcg dimer block the binding of the anti-idiotype whereas the binding of one molecule of bis(DNP)lysine has no significant effect on the idiotype-anti-idiotype system. Previous crystallographic analyses indicated that bound rhodamine 123 protrudes outside the rim while bis(DNP)lysine is completely immersed in the cavity. At high concns bis(DNP)lysine penetrates through the floor of the main cavity and forms a virtually irreversible complex with the dimer. Production of this complex is accompanied by conformational changes, which are presumed to be correlated with observed inhibition of binding with the anti-idiotype M3.9. Expression of the idiotope probably involves more than one linear sequence since reduction and alkylation of the intra- and inter-chain disulphide bonds in 8 M urea leads to a complete loss of binding of the anti-idiotype. The inhibition data suggest involvement of residues on or near the rim of the main cavity. Distribution of potential contact residues for rhodamine 123 is asymmetric only in the case of
aspartic acid
97, which is located on the cavity rim in only one conformational isomer (monomer 2). The homologous residue in monomer 1 is directed away from the cavity and is unlikely to participate in the epitope recognized by M3.9. Attempts to define the epitope in more detail by simulation with multiple peptides have been initiated in collaboration with the laboratory of H. M. Geysen.
Mol
Immunol 1987 Sep
PMID:Localization of an idiotope on the L chain dimer and intact IgG1 immunoglobulin from the patient Mcg. 311 12
To study the relationship between the primary structure of transforming growth factor alpha (TGF-alpha) and some of its functional properties (competition with epidermal growth factor (EGF) for binding to the EGF receptor and induction of anchorage-independent growth), we introduced single amino acid mutations into the sequence for the fully processed, 50-amino-acid human TGF-alpha. The wild-type and mutant proteins were expressed in a vector by using a yeast alpha mating pheromone promoter. Mutations of two amino acids that are conserved in the family of the EGF-like peptides and are located in the carboxy-terminal part of TGF-alpha resulted in different biological effects. When
aspartic acid
47 was mutated to alanine or asparagine, biological activity was retained; in contrast, substitutions of this residue with serine or glutamic acid generated mutants with reduced binding and colony-forming capacities. When leucine 48 was mutated to alanine, a complete loss of binding and colony-forming abilities resulted; mutation of leucine 48 to isoleucine or methionine resulted in very low activities. Our data suggest that these two adjacent conserved amino acids in positions 47 and 48 play different roles in defining the structure and/or biological activity of TGF-alpha and that the carboxy terminus of TGF-alpha is involved in interactions with cellular TGF-alpha receptors. The side chain of leucine 48 appears to be crucial either indirectly in determining the biologically active conformation of TGF-alpha or directly in the molecular recognition of TGF-alpha by its receptor.
Mol
Cell Biol 1988 Mar
PMID:Transforming growth factor alpha: mutation of aspartic acid 47 and leucine 48 results in different biological activities. 328 78
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