scholarly journals Complete nucleotide sequence of a mouse VL30 retro-element.

1988 ◽  
Vol 8 (8) ◽  
pp. 2989-2998 ◽  
Author(s):  
S E Adams ◽  
P D Rathjen ◽  
C A Stanway ◽  
S M Fulton ◽  
M H Malim ◽  
...  

The complete nucleotide sequence of a mouse retro-element is presented. The cloned element is composed of 4,834 base pairs (bp) with long terminal repeats of 568 bp separated by an internal region of 3,698 bp. The element did not appear to have any open reading frames that would be capable of encoding the functional proteins that are normally produced by retro-elements. However, some regions of the genome showed some homology to retroviral gag and pol open reading frames. There was no region in VL30 corresponding to a retroviral env gene. This implies that VL30 is related to retrotransposons rather than to retroviruses. The sequence also contained regions that were homologous to known reverse transcriptase priming sites and viral packaging sites. These observations, combined with the known transcriptional capacity of the VL30 promoter, suggest that VL30 relies on protein functions of other retro-elements, such as murine leukemia virus, while maintaining highly conserved cis-active promoter, packaging, and priming sites necessary for its replication and cell-to-cell transmission.

1988 ◽  
Vol 8 (8) ◽  
pp. 2989-2998
Author(s):  
S E Adams ◽  
P D Rathjen ◽  
C A Stanway ◽  
S M Fulton ◽  
M H Malim ◽  
...  

The complete nucleotide sequence of a mouse retro-element is presented. The cloned element is composed of 4,834 base pairs (bp) with long terminal repeats of 568 bp separated by an internal region of 3,698 bp. The element did not appear to have any open reading frames that would be capable of encoding the functional proteins that are normally produced by retro-elements. However, some regions of the genome showed some homology to retroviral gag and pol open reading frames. There was no region in VL30 corresponding to a retroviral env gene. This implies that VL30 is related to retrotransposons rather than to retroviruses. The sequence also contained regions that were homologous to known reverse transcriptase priming sites and viral packaging sites. These observations, combined with the known transcriptional capacity of the VL30 promoter, suggest that VL30 relies on protein functions of other retro-elements, such as murine leukemia virus, while maintaining highly conserved cis-active promoter, packaging, and priming sites necessary for its replication and cell-to-cell transmission.


2000 ◽  
Vol 74 (7) ◽  
pp. 3149-3155 ◽  
Author(s):  
Mei Huang ◽  
Dora Chin-Yen Koh ◽  
Li-Juan Weng ◽  
Min-Li Chang ◽  
Yun-Kiam Yap ◽  
...  

ABSTRACT The complete nucleotide sequence of hibiscus chlorotic ringspot virus (HCRSV) was determined. The genomic RNA (gRNA) is 3,911 nucleotides long and has the potential to encode seven viral proteins in the order of 28 (p28), 23 (p23), 81 (p81), 8 (p8), 9 (p9), 38 (p38), and 25 (p25) kDa. Excluding two unique open reading frames (ORFs) encoding p23 and p25, the ORFs encode proteins with high amino acid similarity to those of carmoviruses. In addition to gRNA, two 3′-coterminated subgenomic RNA (sgRNA) species were identified. Full-length cDNA clones derived from gRNA and sgRNA were constructed under the control of a T7 promoter. Both capped and uncapped transcripts derived from the full-length genomic cDNA clone were infectious. In vitro translation and mutagenesis assays confirmed that all the predicted ORFs except the ORF encoding p8 are translatable, and the two novel ORFs (those encoding p23 and p25) may be functionally indispensable for the viral infection cycle. Based on virion morphology and genome organization, we propose that HCRSV be classified as a new member of the genus Carmovirus in familyTombusviridae.


2002 ◽  
Vol 184 (12) ◽  
pp. 3194-3202 ◽  
Author(s):  
Takahiro Murata ◽  
Makoto Ohnishi ◽  
Takeshi Ara ◽  
Jun Kaneko ◽  
Chang-Gyun Han ◽  
...  

ABSTRACT Rts1, a large conjugative plasmid originally isolated from Proteus vulgaris, is a prototype for the IncT plasmids and exhibits pleiotropic thermosensitive phenotypes. Here we report the complete nucleotide sequence of Rts1. The genome is 217,182 bp in length and contains 300 potential open reading frames (ORFs). Among these, the products of 141 ORFs, including 9 previously identified genes, displayed significant sequence similarity to known proteins. The set of genes responsible for the conjugation function of Rts1 has been identified. A broad array of genes related to diverse processes of DNA metabolism were also identified. Of particular interest was the presence of tus-like genes that could be involved in replication termination. Inspection of the overall genome organization revealed that the Rts1 genome is composed of four large modules, providing an example of modular evolution of plasmid genomes.


1994 ◽  
Vol 14 (7) ◽  
pp. 4485-4492 ◽  
Author(s):  
B A Dombroski ◽  
Q Feng ◽  
S L Mathias ◽  
D M Sassaman ◽  
A F Scott ◽  
...  

L1 elements constitute a highly repetitive human DNA family (50,000 to 100,000 copies) lacking long terminal repeats and ending in a poly(A) tail. Some L1 elements are capable of retrotransposition in the human genome (Kazazian, H. H., Jr., C. Wong, H. Youssoufian, A. F. Scott, D. G. Phillips, and S.E. Antonarakis, Nature (London) 332:164-166, 1988). Although most are 5' truncated, a consensus sequence of complete L1 elements is 6 kb long and contains two open reading frames (ORFs) (Scott, A. F., B. J. Schmeckpeper, M. Abdelrazik, C. T. Comey, B. O'Hara, J. P. Rossiter, T. Cooley, P. Health, K. D. Smith, and L. Margolet, Genomics 1:113-125, 1987). The protein encoded by ORF2 has reverse transcriptase (RT) activity in vitro (Mathias, S. L., A. F. Scott, H. H. Kazazian, Jr., J. D. Boeke, and A. Gabriel, Science 254:1808-1810, 1991). Because L1 elements are so numerous, efficient methods for identifying active copies are required. We have developed a simple in vivo assay for the activity of L1 RT based on the system developed by Derr et al. (Derr, L. K., J. N. Strathern, and D. J. Garfinkel, Cell 67:355-364, 1991) for yeast HIS3 pseudogene formation. L1 ORF2 displays an in vivo RT activity similar to that of yeast Ty1 RT in this system and generates pseudogenes with unusual structures. Like the HIS3 pseudogenes whose formation depends on Ty1 RT, the HIS3 pseudogenes generated by L1 RT are joined to Ty1 sequences and often are part of complex arrays of Ty1 elements, multiple HIS3 pseudogenes, and hybrid Ty1/L1 elements. These pseudogenes differ from those previously described in that there are base pairs of unknown origin inserted at several of the junctions. In two of three HIS3 pseudogenes studied, the L1 RT appears to have jumped from the 5' end of a Ty1/L1 transcript to the poly(A) tract of the HIS3 RNA.


1999 ◽  
Vol 67 (3) ◽  
pp. 1277-1286 ◽  
Author(s):  
Stephen J. Billington ◽  
Andrea S. Huggins ◽  
Priscilla A. Johanesen ◽  
Paul K. Crellin ◽  
Jackie K. Cheung ◽  
...  

ABSTRACT The vrl locus is preferentially associated with virulent isolates of the ovine footrot pathogen, Dichelobacter nodosus. The complete nucleotide sequence of this 27.1-kb region has now been determined. The data reveal that the locus has a G+C content much higher than the rest of the D. nodosuschromosome and contains 22 open reading frames (ORFs) encoding products including a putative adenine-specific methylase, two potential DEAH ATP-dependent helicases, and two products with sequence similarity to a bacteriophage resistance system. These ORFs are all in the same orientation, and most are either overlapping or separated by only a few nucleotides, suggesting that they comprise an operon and are translationally coupled. Expression vector studies have led to the identification of proteins that correspond to many of these ORFs. These data, in combination with evidence of insertion of vrl into the 3′ end of an ssrA gene, are consistent with the hypothesis that the vrl locus was derived from the insertion of a bacteriophage or plasmid into the D. nodosusgenome.


2004 ◽  
Vol 85 (7) ◽  
pp. 2099-2102 ◽  
Author(s):  
Kai-Shu Ling ◽  
Hai-Ying Zhu ◽  
Dennis Gonsalves

This study reports on the complete genome sequence of Grapevine leafroll-associated virus 3, the type member of the genus Ampelovirus. The genome is 17 919 nt in size and contains 13 open reading frames (ORFs). Previously, the sequence of 13 154 nt of the 3′-terminal of the genome was reported. The newly sequenced portion contains a 158 nt 5′ UTR, a single papain-like protease and a methyltransferase-like (MT) domain. ORF1a encodes a large polypeptide with a molecular mass of 245 kDa. With a predicted +1 frameshift, the large fusion protein generated from ORF1a/1b would produce a 306 kDa polypeptide. Phylogenetic analysis using MT domains further supports the creation of the genus Ampelovirus for mealy-bug-transmitted viruses in the family Closteroviridae.


1990 ◽  
Vol 10 (6) ◽  
pp. 3027-3035
Author(s):  
J D Ohmen ◽  
K A Burke ◽  
J E McEwen

PET122 is one of three nuclear genes specifically required for translation of the mitochondrial mRNA for cytochrome c oxidase subunit III in Saccharomyces cerevisiae. The nucleotide sequence of 2,862 base pairs (bp) of yeast genomic DNA encompassing the PET122 locus shows very close spacing between the PET122 gene (254 codons) and two unidentified open reading frames, termed ORF2 and ORF3. ORF2 is encoded by the same strand of DNA as PET122 and is located 53 bp downstream of PET122, while ORF3 is encoded on the opposite strand and is located 215 bp upstream of PET122. Five transcripts, with sizes of 2.9, 2.3, 2.1, 1.5, and 1.4 kilobases (kb), are produced from this locus. The 2.1- and 1.4-kb transcripts encode ORF3, the 1.5-kb transcript encodes ORF2, and the 2.9- and 2.3-kb transcripts encode PET122. A particularly interesting feature of the ORF3-PET122-ORF2 transcription unit is a 535-base overlap between the 2.3-kb PET122 transcript produced from one strand and a 2.1-kb ORF3 transcript produced from the opposite strand. Similarly, the 2.9-kb PET122 transcript overlaps the 2.1-kb ORF3 transcript by more than 900 bases and the 1.5-kb ORF3 transcript by at least 200 bases. Hence, these pairs of transcripts are antisense to one another and have the potential to regulate, in an interdependent fashion, the posttranscriptional expression of ORF3 and PET122.


1999 ◽  
Vol 181 (19) ◽  
pp. 6214-6219 ◽  
Author(s):  
Rosario Muñoz ◽  
Marta Mollerach ◽  
Rubens López ◽  
Ernesto García

ABSTRACT The complete nucleotide sequence of the capsular gene cluster (cap8) responsible for the biosynthesis of the capsular polysaccharide of Streptococcus pneumoniae type 8 has been determined. The cap8 gene cluster, located between the genes dexB and aliA, is composed of 12 open reading frames. A 14.7-kb DNA fragment embracing the cap8genes was sufficient to transform an unencapsulated type 3 S. pneumoniae strain to a strain with the type 8 capsule. A possible scenario for the evolution of pneumococcal types 2 and 8 is outlined.


1990 ◽  
Vol 10 (6) ◽  
pp. 3027-3035 ◽  
Author(s):  
J D Ohmen ◽  
K A Burke ◽  
J E McEwen

PET122 is one of three nuclear genes specifically required for translation of the mitochondrial mRNA for cytochrome c oxidase subunit III in Saccharomyces cerevisiae. The nucleotide sequence of 2,862 base pairs (bp) of yeast genomic DNA encompassing the PET122 locus shows very close spacing between the PET122 gene (254 codons) and two unidentified open reading frames, termed ORF2 and ORF3. ORF2 is encoded by the same strand of DNA as PET122 and is located 53 bp downstream of PET122, while ORF3 is encoded on the opposite strand and is located 215 bp upstream of PET122. Five transcripts, with sizes of 2.9, 2.3, 2.1, 1.5, and 1.4 kilobases (kb), are produced from this locus. The 2.1- and 1.4-kb transcripts encode ORF3, the 1.5-kb transcript encodes ORF2, and the 2.9- and 2.3-kb transcripts encode PET122. A particularly interesting feature of the ORF3-PET122-ORF2 transcription unit is a 535-base overlap between the 2.3-kb PET122 transcript produced from one strand and a 2.1-kb ORF3 transcript produced from the opposite strand. Similarly, the 2.9-kb PET122 transcript overlaps the 2.1-kb ORF3 transcript by more than 900 bases and the 1.5-kb ORF3 transcript by at least 200 bases. Hence, these pairs of transcripts are antisense to one another and have the potential to regulate, in an interdependent fashion, the posttranscriptional expression of ORF3 and PET122.


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