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P Yot

Publications and source records attributed to P Yot.

35 records · Page 2Linked to original sources
PubMed1979

A simple and fast electrophoretic method for elution of nucleic acids from gels.

A very convenient electrophoretic procedure for DNA or RNA elution from agarose or polyacrylamide gels is described. The gel piece with nucleic acid to be eluted is contained in a dialysis bag filled with buffer and elution is carried out in a horizontal electrophoresis apparatus. The nucleic acid is recovered with a high yield and can be used, without prior treatment, in further enzymatic or chemical reactions. Results obtained with DNA are presented here.

DNA↗
PubMed1979

A restriction map of cauliflower mosaic virus DNA (strain PV 147). Mapping of the cleavage sites of HhaI, SacI, AvaI, PvuII, PstI, XbaI, EcoRI, Bg/II, HincII, HpaII and HindII + III.

The virion-extracted DNA (Mr5 x 10(6)) of cauliflower mosaic virus (CaMV) has three single-stranded interruptions. The mapping of this DNA using eleven restriction endonucleases (HhaI, SacI, AvaI, PvuII, PstI, XbaI, EcoRI, Bg/II, HincII, HpaII and HindII + III) is reported here. The existence of the three single-stranded breaks complicates the identification and the molecular weight determination of fragments produced by HpaII, HindIII and HindII + III. Indeed the electrophoretic mobility of some fragments in which a single-stranded discontinuity is located is modified, and the fluorescence of ethidium bromide complexed with these fragments is reduced as compared to that observed for the other fragments existing in a molar ratio. These drawbacks were overcome by performing experiments of nick-translation of CaMV DNA with Escherichia coli DNA polymerase I. FRom the data it follows that the CaMV DNA molecule bears bears 1 site for HhaI and SacI, 2 for AvaI and PvuII, 3 for PstI, 4 for XbaI, 5 for EcoRI, 6 for Bg/II and HincII, 11 for HpaII and 15 for HindII + III. The corresponding fragments have all been ordered and precisely located providing a suitable map for further investigations connected with the study of the fine structure and the function of the CaMV genome.

DNA Restriction Enzymes↗
PubMed1979

Separation and partial characterization of two deoxyribonucleic acid polymerases from Spiroplasma citri.

The separation and partial characterization of two deoxyribonucleic acid polymerases from Spiroplasma citri have been achieved. The two enzymes had different elution properties on diethylaminoethyl (DEAE) cellulose and differed in their sensitivity to N-ethylmaleimide (NEM), preference for different template-primers, and sedimentation velocity in linear glycerol gradients. The first enzyme activity, ScA, was retained on DEAE-cellulose and was not inhibited by NEM. Activated deoxyribonucleic acid and poly(dA)-oligo(dT12) were the preferred template-primers. Arabinosyl-cytidine triphosphate had no effect. The sedimentation coefficient of ScA was 6.3s. The second activity, ScB, was not retained on DEAE-cellulose and was inhibited by NEM. Poly(dA)-oligo(dT12) was the preferred template-primer, whereas activated DNA was only poorly utilized. ScB was not affected by arabinosyl-cytidine triphosphate, and its sedimentation coefficient was 4.4s. The polymerization activities of the two enzymes were maximum at 37 to 40 degrees C.

Arabinofuranosylcytosine Triphosphate↗
PubMed1978

Studies on the single-stranded discontinuities of the cauliflower mosaic virus genome.

The Cauliflower Mosaic Virus (CaMV) genome is a double-stranded DNA molecule of about 5 million daltons. Native DNA molecules appear heterogeneous when analysed by gel electrophoresis. We have examined the nature of this apparent heterogeneity. Besides, this genome is shown here to contain three single-stranded breaks, as revealed by different denaturation experiments: heating at 75 degrees C, treatment with NaOH or dimethyl sulfoxide (DMSO). Labelling with terminal transferase proves that the 3' ends at these interruptions all have free hydroxyl groups. Electron microscopy and alkaline gel electrophoresis indicate that these three discontinuities are shared by both strands, and that they are not randomly located. S1 nuclease is active on CaMV DNA and generates three fragments. The comparison between the sizes of these fragments and of the products of denaturation leads us to consider that S1 acts at the level of the interruptions. We have determined that two of them, distant by one third genome unit, are in the same strand; the other is in the opposite strand, distant by one sixth genome unit from the nearest other one. The combined use of restriction enzymes and S1 nuclease has enabled us to locate these three discontinuities on the restriction map of the CaMV genome that we have otherwise established.

Chromosome Mapping↗
PubMed1977

Heterogeneity of the kinetoplast DNA molecules of Trypanosoma cruzi.

Kinetoplast DNA (kDNA) of the culture form of Trypanosoma cruzi is cleaved by restriction endonucleases (HpaII, HindII, EcoRI, and HaeIII). The analysis of the cleavage patterns proves that the minicircles (free circulargenome units) are heterogeneous in base sequences. The same results are obtained with the complex kDNA network which is composed of the association of minicircles and linear molecules. Kinetic studies of the renaturation of kDNA previously cleaved by HpaII into fragments of the genome unit size show at least two populations of molecules. About 75% of these molecules correspond to the fast renaturing population having the molecular complexity of the minicircles. The molecules of the slow renaturing population have a much higher molecular complexity than the minicircles and do not seem to be related to the majority of the long linear molecules.

Chemical Phenomena↗
PubMed1975

[Study of kinetoplast DNA of Trypansoma cruzi using restriction endonucleases].

The cleavage of kinetoplastic DNA (kDNA) with the restriction endonucleases (Eco RI, Hind II + III, Hpa II) was studied. The quantitative data of electrophoretically separated fragments show that the kDNA (free circular genome units and complex network) is composed of distinct populations of circles. Kinetic studies of renaturation of kDNA previously cleaved by Hpa II into fragments having the length of one genome unit also indicate the presence of at least two and probably three populations of molecules.

DNA↗
PubMed1975

Determination of genes, restriction sites, and DNA sequences surrounding the 6S RNA template of bacteriophage lambda.

A major product of the transcription of bacteriophage lambda DNA in vitro is the 6S RNA. This article presents a detailed mapping of restriction endonuclease cleavage sites about the region of the 6S RNA template within the lambda genome. Restriction fragments defined by these sites have been used to localize the 6S RNA template within the physical and genetic maps of the lambda genome. Nucleotide sequence analysis of one of these fragments has largely confimed the nucleotide sequence of the 6S RNA reported previously and has indicated the sequence of DNA that immediately follows the 6S RNA template. This article reports the nucleotide sequence following a known site of transcription termination by RNA polymerase of Escherichia coli.

Base Sequence↗
PubMed1974

The 5'-terminal nucleotide sequence of galactose messenger ribonucleic acid of Escherichia coli.

The 5'-terminal sequence of mRNA from the galactose operon of E. coli has been determined. gal RNA is synthesized in vitro by means of a kinetically controlled purified transcription system and is isolated by a two-step RNA.DNA hybridization scheme. The following sequence of the first 77 nucleotides has been deduced by analysis of oligonucleotides produced by digestion with T(1), pancreatic, and carboxymethylated pancreatic ribonucleases: ppA-U-A-C-C-A-U-A-A-G-C-C-U-A-A-U-G-G-A-G-C-G-A-A-U-U-A-U-G-A-G-A-G-U-U-C-U-G-G-U-U-A-C-C-G-G-U-G-G-U-A-G-C-G-G-U-U-A-C-A-U-U-G-G-A-A-G-U-C-A-U-A-C-C-U-G-U. Residues 27-77 correspond to the amino terminal 17 amino acids of UDPgalactose 4-epimerase (EC 5.1.3.2), the protein specified by the promoter-proximal structural gene of the operon. A self-complementary sequence occurs near the 5' terminus; 12 of 15 nucleotides between residues 4 and 18 are symmetrically located about position 11. The sequence of residues 22-33 closely resembles part of the lactose operator sequence reported previously [Gilbert, W. & Maxam, A. (1973) Proc. Nat. Acad. Sci. USA 70, 3581-3584].

Amino Acid Sequence↗
PubMed1970

Valine-specific tRNA-like structure in turnip yellow mosaic virus RNA.

The 3' terminal nucleotide of turnip yellow mosaic virus (TYMV) RNA (23-25 S) may be esterified with valine in the presence of ATP and an enzyme preparation from Escherichia coli. The nucleotide composition near the valine-binding site is different for TYMV RNA and tRNA(Val) from cabbage, as shown by comparison of the valine adducts of nucleotides labeled with radioactive valine in T(1) RNase digests. Consequently, host tRNA(Val) is not involved in the observed charging of TYMV RNA with valine. The TYMV RNA appears to have a tRNA-like structure, at or near its 3' end, that is recognized by three different enzymes which specifically catalyze reactions involving tRNA.

Binding Sites↗
PubMed1968

Hydrolyse des aminoacyl-tARN par la phosphodiesterase du venin.

The influence of the esterification of the 3'(2') hydroxyl group of tRNA on the hydrolysis by venom phosphodiesterase (Crotalus adamanteus) was studied. It was shown that this esterification does not change the rate of hydrolysis. At pH 7-8, no significant differences were observed either when the alpha amino group of the attached amino acid was free or blocked, or when the aminoacid contained a free carboxyl group or a second amino group (glutamic acid or lysine). Aminoacyl-AMP or oligopeptidyl-AMP can be prepared by this method.

Journal Article↗