Comparative sequence analysis of plasmids pME2001 and pME2200 of methanothermobacter marburgensis strains Marburg and ZH3
| Autor: | Thomas Leisinger, Yongneng Luo, Alain Wasserfallen |
|---|---|
| Rok vydání: | 2001 |
| Předmět: |
DNA Replication
Methanobacteriaceae Sequence analysis Molecular Sequence Data Biology Plasmid Bacterial Proteins Methanothermobacter marburgensis Escherichia coli Direct repeat RNA Antisense Replicon Amino Acid Sequence ORFS Molecular Biology Genetics Adenosine Triphosphatases Base Sequence Sequence Homology Amino Acid Escherichia coli Proteins DNA Helicases Sequence Analysis DNA biology.organism_classification Open reading frame DNA Archaeal Codon usage bias Nucleic Acid Conformation Plasmids |
| Zdroj: | Plasmid. 45(1) |
| ISSN: | 0147-619X |
| Popis: | Comparison of the updated complete nucleotide sequences of the two related plasmids pME2001 and pME2200 from the thermophilic archaeon Methanothermobacter marburgensis (formerly Methanobacterium thermoautotrophicum) strains Marburg and ZH3, respectively, revealed an almost identical common backbone structure and five plasmid-specific inserted fragments (IFs), four of which are flanked by perfect or nearly perfect direct repeats 25-52 bp in length. A 4354-bp minimal replicon was derived from the alignment of the two plasmids, which encodes one putative antisense RNA related to replication control and five open reading frames (ORFs) organized in two operons. The first operon consists of four ORFs, the third of which, i.e. ORF3, contains a helix-turn-helix motif and a purine NTP-binding motif often found in proteins involved in DNA metabolic processes. The database search results suggest that ORF3 might function as a replication initiator protein. The large putative Rep protein encoded by pME2001 was overexpressed in Escherichia coli as an N-terminal His-tagged version using pET28a and a compatible helper plasmid that coexpresses minor tRNAs, argU and ileX to compensate for codon usage difference. ORFs 1, 2, and 3 are organized in a sequence reminiscent of that described in E. coli plasmids of the R1 family, cop-tap-rep. ORF6 encoded by IF1, one of the pME2200-specific elements, showed significant similarity to ORF6 encoded by archaeal phage psiM2 of M. marburgensis strain Marburg and may confer the apparent immunity of its host strain ZH3 to infection by phage psiM2. Our data indicate that M. marburgensis plasmids may evolve by a series of gene duplication and excision events. |
| Databáze: | OpenAIRE |
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