Abstract |
A reverse transcriptase (RT) was recently found in Myxococcus xanthus, a Gram-negative soil bacterium. This RT has been shown to be associated with a chromosomal region designated a retron responsible for the synthesis of a peculiar extrachromosomal DNA called msDNA (multicopy single-stranded DNA). We demonstrate that M. xanthus contains two independent, unlinked retrons, one for the synthesis of msDNA-Mx162 and the other for msDNA-Mx65. The structural analysis of the retron for msDNA-Mx65 revealed that the coding regions for msdRNA (msr) and msDNA (msd), and an open reading frame (ORF) downstream of msr are arranged in the same manner as found for the Mx162 retron. The ORF encodes a polypeptide of 427 amino acid residues. The amino-terminal domain (residues 1-138) shows no striking similarity to these proteins presently available in the data bases including the msDNA-Mx162 ORF, while the sequence from residues 139-394 can be aligned with various known RT sequences and has 47% identity with the RT domain of the msDNA-Mx162 ORF. On the basis of these findings, possible origins of two highly diverse retrons on the M. xanthus chromosome are discussed.
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Authors | S Inouye, P J Herzer, M Inouye |
Journal | Proceedings of the National Academy of Sciences of the United States of America
(Proc Natl Acad Sci U S A)
Vol. 87
Issue 3
Pg. 942-5
(Feb 1990)
ISSN: 0027-8424 [Print] United States |
PMID | 1689062
(Publication Type: Comparative Study, Journal Article, Research Support, Non-U.S. Gov't, Research Support, U.S. Gov't, P.H.S.)
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Chemical References |
- Codon
- RNA-Directed DNA Polymerase
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Topics |
- Amino Acid Sequence
- Base Sequence
- Chromosome Deletion
- Codon
(genetics)
- Genes, Bacterial
- Molecular Sequence Data
- Mutation
- Myxococcales
(enzymology, genetics)
- RNA-Directed DNA Polymerase
(genetics)
- Restriction Mapping
- Sequence Homology, Nucleic Acid
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