Comparative Study of different msDNA (multicopy single-stranded DNA) structures and phylogenetic comparison of reverse transcriptases (RTs): evidence for vertical inheritance



Rasel Das1, Tadashi Shimamoto2, Sultan Mohammad Zahid Hosen3, Mohammad Arifuzzaman1*



1Department of Biochemistry and Biotechnology, University of Science and Technology Chittagong (USTC), Foy’s Lake, Pahartali Chittagong 4202, Bangladesh; 2Laboratory of Food Microbiology and Hygiene, Graduate School of Biosphere Science, Hiroshima University, Higashi-Hiroshima, Hiroshima 739-8528, Japan; 3Department of Pharmacy, BGC Trust University, Bangladesh.


Email; *Corresponding author



+91-880-31-659070-71 Ext: 280





Article Type




Received September 26, 2011; Accepted October 02, 2011; Published October 14, 2011



The multi-copy single-stranded DNA (msDNA) is yielded by the action of reverse transcriptase of retro-element in a wide range of pathogenic bacteria. Upon this phenomenon, it has been shown that msDNA is only produced by Eubacteria because many Eubacteria species contained reverse transcriptase in their special retro-element. We have screened around 111 Archaea at KEGG (Kyoto Encyclopedia of Genes and Genomes) database available at genome net server and observed three Methanosarcina species (M.acetivorans, M.barkeri and M.mazei), which also contained reverse transcriptase in their genome sequences. This observation of reverse transcriptase in Archaea raises questions regarding the origin of this enzyme. The evolutionary relationship between these two domains of life (Eubacteria and Archaea) hinges upon the phenomenon of retrons. Interestingly, the evolutionary trees based on the reverse transcriptases (RTs) and 16S ribosomal RNAs point out that all the Eubacteria RTs were descended from Archaea RTs during their evolutionary times. In addition, we also have shown some significant structural features among the newly identified msDNA-Yf79 in Yersinia frederiksenii with other of its related msDNAs (msDNA-St85, msDNA-Vc95, msDNA-Vp96, msDNA-Ec78 and msDNA-Ec83) from pathogenic bacteria. Together the degree of sequence conservation among these msDNAs, the evolutionary trees and the distribution of these ret (reverse transcriptase) genes suggest a possible evolutionary scenario. The single common ancestor of the organisms of Eubacteria and Archaea subgroups probably achieved this ret gene during their evolution through the vertical descent rather than the horizontal transformations followed by integration into this organism genome by a mechanism related to phage recognition and/or transposition.



msDNA, reverse transcriptase, phylogenetic tree



Das et al. Bioinformation 7(4): 176-179 (2011)

Edited by

P Kangueane






Biomedical Informatics



This is an Open Access article which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly credited. This is distributed under the terms of the Creative Commons Attribution License.