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W Fiers

Publications and source records attributed to W Fiers.

At least 451 records · Page 25Linked to original sources

The enzymic addition of poly(A) to the 3'-end of RNA using bacteriophage MS 2 RNA as a model system.

ATP : RNA adenyltransferase, purified from Escherichia coli, was used to add a series of adenosine residues to the 3'-end of MS2RNA. Incubations of the order of a few minutes at 37 degrees C were sufficient for synthesis of a short poly(A) chain that did not appreciably alter the hydrodynamic or electrophoretic properties of MS2 RNA. The size of the poly(A) tails was estimated by gel electrophoresis after prior hydrolysis of the primer RNA with pancreatic ribonuclease. These results were in good agreement with the values calculated on the basis of the relative amount of incorporated AMP. After the addition of a short poly(A) tail, approximately 50% of the treated material binds specifically to an oligo(dT)-cellulose column. The majority of the recovered poly(a)-containing RNA was still intact, as shown by analysis on polyacrylamide gel. After incubations beyond 6 min, slowly sedimenting material, also showing reduced electrophoretic mobility, was formed. Presumably this material corresponds to RNA chains to which long poly(A) tails are linked.

Centrifugation, Zonal↗

Cleavage map of the simian-virus-40 genome by the restriction endonuclease III of Haemopholus aegyptius.

Enzymic digestion of Simian virus 40 (SV40) DNA with Haemophilus aegyptius restriction endonuclease Hae III results in 10 major and eight minor fragments. These were resolved by electrophoresis on graduated polyacrylamide slab gels. All fragments have been characterized with respect to the size relative to the Haemophilus influenzae Rd fragments (Hind). They were ordered on the SV40 DNA map by means of overlap analysis of the double cleavage products derived from sequential digestion of Hind fragments with Hae III endonuclease and Hae fragments with Hind II + III enzyme, as well as by other reciprocal cleavage experiments, including those involving Haemophilus para-influenzae fragments. In this way the 18 Hae III cleavage sites and the 13 Hind sites have been localized on the circular SV40 DNA map.

Base Sequence↗

Specific cleavage and physical mapping of simian-virus-40 DNA by the restriction endonuclease of Arthrobacter luteus.

Simian virus 40 (SV40) DNA (strain 776) is cleaved by the restriction endonuclease from Arthrobacter luteus into 32 specific fragments including 20 large pieces designated Alu-A through T as well as 12 minor products named Alu m1 through m8. These were mapped on the SV40 genome by double digestion experiments. Alu fragments were treated with Hind enzymes and vice versa. Similar reciprocal digestions were also carried out with Hae III enzyme. In this way a detailed cleavage map of the SV40 genome could be constructed.

Arthrobacter↗

The initiation region of the SV40 VP1 gene.

The sequence of 15 nucleotides located at the 5' terminus of the plus strand of the SV40 Hind K fragment has been determined as (5') A-G-C-T-T-A-T-G-A-A-G-A-T-G-G (3'). The 3' on OH terminal G of this segment is part of the G-C-C codeword for the N terminal alanine of the VP1 protein. This region therefore presumably corresponds to a ribosome binding site on the 16S late mRNA. Complementarily to the 3' OH of eucaryotic 18S ribosomal RNA and homology with the BMV coat ribosome binding site are discussed.

Bacterial Proteins↗

Nucleotide sequence of the restriction fragments hind L and hind M of SV40 DNA.

The nucleotide sequence of the two minor SV40 DNA restriction fragments Hind L and Hind M is here reported. For this purpose we used 5'-32p-labeled DNA fragments either partially digested with snake venom diesterase for analysis by the wandering spot method or partially degraded with the base specific reagents dimethylsulphate or hydrazine for direct sequence analysis on gel. In the former procedure the strands were separated before degradation, while in the latter the strands were separated after modification but before the degradation. Due to the presence of several termination codons, the region Hind L - Hind M cannot be translated in a polypeptide. Also, no initiation codons for protein synthesis are present in this region.

Base Sequence↗

3'-Terminal nucletide sequence (n equals 361) of bacteriophage MS2 RNA.

32P-Labeled MS2 RNA was partially digested with ribonuclease T1 (guanyloribonuclease; ribonucleate 3'-guanylo-oligonucleotidohydrolase; EC 3.1.4.8) or with epilson-carboxymethyl-lysine-41 pancreatic ribonuclease A (ribonucleate 3'-pyrimidino-oligonucleotidohydrolase; EC 3.1.4.22). A series of overlapping fragments was obtained which allowed the reconstruction of a 361-nucleotide-long 3'-terminal sequence. A unique reading frame could be deduced, which indicated that the replicase gene ends with a U-A-G termination signal and is followed by a 174-nucleotide-long untranslated segment.

Base Sequence↗

Deoxynucleotide substitution: a new technique for sequence analysis of RNA.

It is possible to replace in a normal transcription reaction catalyzed by E.coli RNA polymerase one of the four precursors by the corresponding deoxynucleoside triphosphate. These deoxynucleotide-substituted RNA's offer interesting prospects for nucleotide sequence analysis. Indeed by the use of U(2)-RNase with dG-RNA, or pancreatic RNase with dC-RNA or dU-RNA, base specific cleavage can be obtained at any of the four residues. In this way overlap of at least six residues in length can be obtained for any site in the RNA. The technique offers also great benefit for solving the sequence of the more difficult T(1)-oligonucleotides. Some examples in the sequence analysis of SV40 DNA-Hind fragments are reported.

Animals↗

Picornaviridae.

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Enterovirus↗