کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
5912887 | 1161621 | 2013 | 7 صفحه PDF | دانلود رایگان |

- Borrelia species carry more plasmids than reported for any other type of bacteria.
- The plasmids come in two flavors: circular and linear with hairpin ends.
- Five parologous protein families confer replication and maintenance functions.
- Recent work suggests that trans complementation amongst plasmids may sometimes occur.
Borrelia species comprise a unique genus of bacterial pathogens. These organisms contain a segmented genome with up to two dozen plasmids ranging in size from 5Â kb up to about 200Â kb. The plasmids have also been referred to as mini-chromosomes or essential genetic elements, as some of them carry information important for infection of vertebrates or for survival in the tick vector. Most of the plasmids are linear with covalently closed hairpin telomeres and these linear plasmids are in a constant state of genetic rearrangement. The mechanisms of plasmid replication, maintenance and partitioning remain largely obscure and are complicated by a long doubling time, the requirement for expensive media and inefficient genetic manipulation. A set of five parologous protein families (PFs) are believed to confer the ability for autonomous replication and plasmid maintenance. The number of plasmids also complicates analyses because of the possibility that PFs from one plasmid may sometimes function in trans on other plasmids. Two papers in the last year have moved the field forward and their combined data suggest that trans complementation amongst Borrelia plasmids may sometimes occur.
Journal: Plasmid - Volume 70, Issue 2, September 2013, Pages 161-167