Mobilization of Cryptic Plasmids in Azospirillum

1988 ◽  
pp. 54-63
Author(s):  
M. Pampaluna ◽  
M. N. Antonelli ◽  
L. Piana ◽  
C. Fogher
Keyword(s):  
2009 ◽  
Vol 2009 ◽  
pp. 1-10 ◽  
Author(s):  
Daniela Lepka ◽  
Tobias Kerrinnes ◽  
Evelyn Skiebe ◽  
Birgitt Hahn ◽  
Angelika Fruth ◽  
...  

We report the nucleotide sequence of two novel cryptic plasmids (4357 and 14 662 base pairs) carried by aYersinia enterocoliticabiotype 1A strain isolated from pork. As distinguished from most biotype 1A strains, this isolate, designated 07-04449, exhibited adherence to eukaryotic cells. The smaller plasmid pYe4449-1 carries five attributable open reading frames (ORFs) encoding the first CcdA/CcdB-like antitoxin/toxin system described for aYersiniaplasmid, a RepA-like replication initiation protein, and mobilizing factors MobA and MobC. The deduced amino acid sequences showed highest similarity to proteins described inSalmonella(CcdA/B),Klebsiella(RepA), andPlesiomonas(MobA/C) indicating genomic fluidity among members of theEnterobacteriaceae. One additional ORF with unknown function, termed ORF5, was identified with an ancestry distinct from the rest of the plasmid. While the C+G content of ORF5 is 38.3%, the rest of pYe4449-1 shows a C+G content of 55.7%. The C+G content of the larger plasmid pYe4449-2 (54.9%) was similar to that of pYe4449-1 (53.7%) and differed from that of theY. enterocoliticagenome (47.3%). Of the 14 ORFs identified on pYe4449-2, only six ORFs showed significant similarity to database entries. For three of these ORFs likely functions could be ascribed: a TnpR-like resolvase and a phage replication protein, localized each on a low C+G island, and DNA primase TraC. Two ORFs of pYe4449-2, ORF3 and ORF7, seem to encode secretable proteins. Epitope-tagging of ORF3 revealed protein expression at4°Cbut not at or above27°Csuggesting adaptation to a habitat outside swine. The hypothetical protein encoded by ORF7 is the member of a novel repeat protein family sharing theDxxGN(x)nDxxGNmotif. Our findings illustrate the exceptional gene pool diversity within the speciesY. enterocoliticadriven by horizontal gene transfer events.


Plasmid ◽  
2003 ◽  
Vol 49 (3) ◽  
pp. 233-252 ◽  
Author(s):  
Zhenping Zhong ◽  
Ron Caspi ◽  
Donald Helinski ◽  
Vic Knauf ◽  
Sean Sykes ◽  
...  

2012 ◽  
Vol 7 (4) ◽  
pp. 571-586 ◽  
Author(s):  
Andrzej Mazur ◽  
Piotr Koper

AbstractSoil bacteria, collectively named rhizobia, can establish mutualistic relationships with legume plants. Rhizobia often have multipartite genome architecture with a chromosome and several extrachromosomal replicons making these bacteria a perfect candidate for plasmid biology studies. Rhizobial plasmids are maintained in the cells using a tightly controlled and uniquely organized replication system. Completion of several rhizobial genome-sequencing projects has changed the view that their genomes are simply composed of the chromosome and cryptic plasmids. The genetic content of plasmids and the presence of some important (or even essential) genes contribute to the capability of environmental adaptation and competitiveness with other bacteria. On the other hand, their mosaic structure results in the plasticity of the genome and demonstrates a complex evolutionary history of plasmids. In this review, a genomic perspective was employed for discussion of several aspects regarding rhizobial plasmids comprising structure, replication, genetic content, and biological role. A special emphasis was placed on current post-genomic knowledge concerning plasmids, which has enriched the view of the entire bacterial genome organization by the discovery of plasmids with a potential chromosome-like role.


1980 ◽  
Vol 28 (3) ◽  
pp. 692-699 ◽  
Author(s):  
Francis L. Macrina ◽  
Patricia H. Wood ◽  
Kevin R. Jones

By using the basic methodology initially published by Kretschmer et al. (J. Bacteriol. 124 :225-231, 1975), we have been able to introduce phenotypically cryptic plasmids from Streptococcus ferus (formerly Streptococcus mutans subsp. ferus ) into Streptococcus sanguis by genetic transformation. In this system, the entry of the cryptic plasmids is selected indirectly. This is effected with transforming deoxyribonucleic acid mixtures in which the cryptic plasmid deoxyribonucleic acid is present in an approximate 10-fold molar excess with respect to a plasmid (pVA1) known to confer erythromycin resistance. Under such conditions, 5 to 10% of the pVA1-containing erythromycin-resistant transformants were cotransformed with cryptic plasmid deoxyribonucleic acid. pVA1 may be selectively eliminated by growth of its S. sanguis host strain at 42°C, enabling the construction of isogenic strains with and without S. ferus cryptic plasmids. Comparative physiological studies of such strains have failed to reveal any plasmid-conferred phenotypes in S. sanguis. With this procedure, we have been able to physically separate two small cryptic plasmids (2.4 × 10 6 and 2.8 × 10 6 daltons) of S. ferus. Although these plasmids were found naturally to exist in a single S. ferus host, they were able to replicate independently of one another in S. sanguis. Restriction enzyme fingerprinting indicated that these plasmids did not share a common ancestry.


2004 ◽  
Vol 32 (2) ◽  
pp. 184-187 ◽  
Author(s):  
D. Prieur ◽  
G. Erauso ◽  
C. Geslin ◽  
S. Lucas ◽  
M. Gaillard ◽  
...  

This minireview summarizes our current knowledge about archaeal genetic elements in the hyperthermophilic order Thermococcales in the phylum Euryarchaeota. This includes recent work on the first virus of Pyrococcus, PAV1, the discovery of novel unique virus morphotypes in hot deep-sea environments, and preliminary observations on novel cryptic plasmids. We also review the work accomplished over the last 5 years in the development of genetic tools for members of the Pyrococcus and Thermococcus genera, mainly in our laboratories.


Gene ◽  
1995 ◽  
Vol 154 (1) ◽  
pp. 77-79 ◽  
Author(s):  
F. Bigey ◽  
B. Grossiord ◽  
C.K.N. Chan Kwo Chion ◽  
A. Arnaud ◽  
P. Galzy

1974 ◽  
Vol 20 (4) ◽  
pp. 551-557
Author(s):  
Paul W. Stiffler ◽  
D. E. Schoenhard

The physical basis of the donor property of Salmonella pullorum donor strains MS8300, MS830, and MS831 carrying the F77 factor from Salmonella typhimurium was investigated by dye-buoyant density equilibrium centrifugation and zonal centrifugation in neutral sucrose gradients. Centrifugation of the MS8300 and MS831 closed circular DNA material in a 20 to 31% neutral sucrose gradient resulted in a profile having one sharp peak of radioactivity with a sedimentation coefficient of 17 S and a broad peak extending from 65 to 70 S. The 17- and 65-S species were isolated from the isogenic F− strain MS83. These appeared identical with those isolated previously in S. pullorum MS53 as the cryptic plasmids PO-1 and PO-2 respectively. Cosedimentation of differentially labeled F77 DNA and the lysate containing the 65-S and 70-S species suggested that the 70-S species is the autonomous F77 factor in strains MS8300 and MS831. Lysates of MS830 similarly treated produced a profile containing the 17-S molecule and possibly some 70-S molecules but no 65-S molecules. It was concluded that the F77 factor was integrated in most cells and that the covalently closed circular state of PO-2 plasmid was lost. The mutation in the cysE gene of the F77 factor carried by MS831 had no apparent effect on the covalently closed circular nature of PO-2 plasmid, although F77 no longer seemed to mobilize the chromosome from the cysE locus.


1999 ◽  
Vol 181 (11) ◽  
pp. 3375-3381 ◽  
Author(s):  
Akira Yamagata ◽  
Junichi Kato ◽  
Ryuichi Hirota ◽  
Akio Kuroda ◽  
Tsukasa Ikeda ◽  
...  

ABSTRACT Two plasmids were discovered in the ammonia-oxidizing bacteriumNitrosomonas sp. strain ENI-11, which was isolated from activated sludge. The plasmids, designated pAYS and pAYL, were relatively small, being approximately 1.9 kb long. They were cryptic plasmids, having no detectable plasmid-linked antibiotic resistance or heavy metal resistance markers. The complete nucleotide sequences of pAYS and pAYL were determined, and their physical maps were constructed. There existed two major open reading frames, ORF1 in pAYS and ORF2 in pAYL, each of which was more than 500 bp long. The predicted product of ORF2 was 28% identical to part of the replication protein of a Bacillus plasmid, pBAA1. However, no significant similarity to any known protein sequences was detected with the predicted product of ORF1. pAYS and pAYL had a highly homologous region, designated HHR, of 262 bp. The overall identity was 98% between the two nucleotide sequences. Interestingly, HHR-homologous sequences were also detected in the genomes of ENI-11 and the plasmidless strain Nitrosomonas europaea IFO14298. Deletion analysis of pAYS and pAYL indicated that HHR, together with either ORF1 or ORF2, was essential for plasmid maintenance in ENI-11. To our knowledge, pAYS and pAYL are the first plasmids found in the ammonia-oxidizing autotrophic bacteria.


1994 ◽  
Vol 124 (3) ◽  
pp. 301-305 ◽  
Author(s):  
David Pridmore ◽  
Tzona Stefanova ◽  
Beat Mollet

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