The ectomycorrhizal basidiomycete Hebeloma circinans harbors a linear plasmid encoding aDNA- and RNA polymerase

The Journal of General and Applied Microbiology

Jürgen Schründer¹  Jean Claude Debaud²  Friedhelm Meinhardt¹  Xiyuan Bai¹ 

[1] Westfälische Wilhelms-Universität Munster, Institut für Mikrobiologie;Université Claude Bernard Lyon 1

关键词: DNA polymerase;    Hebeloma circinans;    linear plasmid;    mycorrhiza;    phylogenetic tree;    RNA polymerase;   

DOI  :  10.2323/jgam.43.273

学科分类：微生物学和免疫学

来源: Applied Microbiology, Molecular and Cellulrar Biosciences Research Foundation

【 摘 要 】

Bulk DNA isolated from the ectomycorrhizal basidiomycete Hebeloma circinans was treated with proteinase K and submitted to agarose gel electrophoresis. In addition to high molecular weight genomic DNA, three minor bands were detected. The band with the highest electrophoretic mobility(2.2kbp) corresponds to double-stranded RNA. The two other bands, termed pHC1 and pHC2, were shown to be dsDNA molecules of 10.3 and 9.1kbp, respectively. Treatment of the pHC elements with 3′- and 5′-specific exonucleases revealed a linear structure and proved that the 5′ ends are protected from digestion; for pHC2, linearity was confirmed by restriction mapping. A 3.2kbp Hindlll fragment of pHC2 was cloned and sequenced; it contains two open reading frames encoding putative viral B type DNA and RNA polymerases. Thus, the fungus harbors a typical linear plasmid, up to now, rarely described for basidiomycetes and hitherto unknown for mycorrhizal species.

【 授权许可】

Unknown