Abstract: The present invention relates to a prokaryotic reverse transcriptase enzyme. The enzyme is capable of synthesizing a hybrid DNA-RNA molecule called msDNA with the genes which synthesize the DNA and RNA portions of the molecule.

Abstract: A method of synthesis of new and useful single-stranded DNAs which have a stem-loop configuration (ss-slDNA). The method is an in vivo or an in vitro synthesis. Replicating vehicles which produce these ss-slDNAs. The ss-slDNAs are described. Uses for these slDNAs are disclosed. They can be used for introducing random mutations, they lend themselves for replication by a variant of the PCR method. They can also be used for regulating gene function. Other uses are disclosed.

Abstract: A multicopy single-stranded DNA (msDNA) synthesizing system in E. coli is disclosed. The use of the msDNA system to synthesize cDNA in vivo is disclosed. Construction of synthetic msDNA is also disclosed. Also processes for gene amplification and for producing a stable RNA are disclosed.

Abstract: Eucaryotic cells like mammal and plant cells transfected with genes, called retrons, which code for stable single-stranded hybrid molecules (msDNA) containing RNA and DNA portions are disclosed. The retrons producing said linked RNA and DNA portions of the msDNAs also contain a gene encoding a reverse transcriptase (RT), which is necessary for the synthesis of the msDNAs. The msDNAs may contain foreign nucleic acid fragments which may be antisense fragments. These msDNA antisense vectors are useful for targeting genes of target proteins.

Abstract: Novel hybrid molecules comprising an RNA and a DNA portion are disclosed. A method for synthesizing the molecule is disclosed.

Abstract: A method of synthesis of new and useful single-stranded DNAs which have a stem-loop configuration (ss-slDNA). The method is an in vivo or an in vitro synthesis. Replicating vehicles which produce these ss-slDNAs. The ss-slDNAs are described. Uses for these slDNAs are disclosed. They can be used for introducing random mutations, they lend themselves for replication by a variant of the PCR method. They can also be used for regulating gene function. Other uses are disclosed.

Abstract: The invention provides a method for synthesizing new and useful single-stranded DNAs which have a stem-loop configuration (ss-slDNA). The method is an in vivo or in vitro synthesis. Replicating vehicles are provided which produce these ss-slDNAs. The slDNAs can be used for introducing random mutations in a selected gene, and they lend themselves for replication by a variant of the PCR method.

Abstract: A method for producing in vivo stable single-stranded DNAs in eucaryotic cells. The DNAs are multicopy single-stranded DNA (msDNA) structures constituted by a RNA and a DNA portion. The group of genes (retrons) producing said coupled RNA and DNA portions of the msDNAs and the gene encoding reverse transcriptase (RT). The transformed eucaryotes harboring these retrons. The new msDNAs which are encoded by the new retrons. The msDNAs can be used as vectors for antisense DNA and for amplification of inserted genes.

Abstract: The common conserved structural features of msDNAs are described. A synthesis of msDNAs is described which involves a necessary reverse transcriptase. Reverse transcriptases are described which have unique properties in the synthesis of cDNAs. Various utilities are described.

Abstract: A multicopy single-stranded DNA (msDNA) synthesizing system in E. coli is disclosed. The use of the msDNA system to synthesize cDNA in vivo is disclosed. Construction of synthetic msDNA is also disclosed. Also processes for gene amplification and for producing a stable RNA are disclosed.

Abstract: The present invention relates to an isolated bacterial reverse transcriptase. The reverse transcriptase synthesizes a peculiar RNA-DNA complex called msDNA which is a single-stranded DNA structure branched out from an RNA molecule. The gene coding for the reverse transcriptase has been isolated and sequenced. It codes for a polypeptide of 485 amino acid residues. This is the first time that a reverse transcriptase has been found, identified and isolated from a prokaryotic microorganism of which the amino acid sequence is shown in FIGS. 2a-2d.

Abstract: msDNA is a peculiar molecule consisting of a branched RNA linked to single-stranded DNA via a 2', 5' phosphodiester bond. A cell-free system, utilizing cells permeablized with phenethyl, alcohol, was established to study the synthesis of msDNA in Myxococcus xanthus. Permeablized cell labeled with [.alpha.-.sup.32 P]dCTP in the presence of ddGTP, ddATP, or ddTTP, produce a band that migrates at the same position as the full-sized msDNA in an acrylamide gel. However, when this band is treated with ribonuclease A prior to gel electrophoresis, it resulted in many bands of different sizes. This indicates that during the labeling, intermediates are produced in which single-stranded DNAs of various lengths are associated with a compensatory length of RNA such that the total length for each intermediate is identical. These results provide evidence for the previously proposed model in which msDNA is synthesized by reverse transcriptase using a folded RNA precursor as a primer as well as a template.