Biomedical subjects

Peter Javorsky

Publications and source records attributed to Peter Javorsky.

5 recordsLinked to original sources

PubMed2005

Multiple restriction-modification systems are present in rumen treponemes.

Type II restriction endonucleases were purified by heparin-sepharose followed by ion chromatography from Treponema strains. The results indicate that in addition to frequently cutting GATC-specific restriction enzymes, the tested strains also possess rarely cutting endonucleases. The purified restriction endonucleases represent four different sequence specificities, comprising isoschizomers of DrdI, AflII, Tth111I and NdeI. The data presented show that three rumen Treponema strains possess altogether seven type II restriction-modification systems. Thus, individual Treponema strains may be considered an interesting source of multiple type II restriction enzymes.

Animals↗

PubMed2005

Occurrence of pS86/pEF47-related plasmids in gram-positive cocci.

A small, low-copy-number cryptic 5.5-kb plasmid, designated pEF47, was isolated from a rumen bacterium Enterococcus faecalis 47 and partially characterized. Comparisons by restriction and partial sequence analysis of pEF47 demonstrated high homology to pS86 plasmid, recently isolated from a human clinical strain E. faecalis S-86. PCR followed by sequence analysis and Southern hybridization showed that pS86/pEF47-related replicons are regularly encountered in plasmids from gram-positive cocci.

Animals↗

PubMed2005

pSRD191, a new member of RepL replicating plasmid family from Selenomonas ruminantium.

A numerous plasmid population was detected in strain 19 of Selenomonas ruminantium. The population was found to consist of six plasmids in size ranging from 1.4 to more than 20kb. The smallest 1.4kb cryptic plasmid pSRD191 was further characterized. Sequence analysis identified a single ORF encoding the 177-residue putative replication protein (Rep191) which shared significant homology with RepL family of replication protein from Firmicutes (staphylococci and bacilli). PCR analysis and Southern hybridisation showed that pSRD191 related plasmids are frequently encountered in rumen selenomonads.

Amino Acid Sequence↗

PubMed2005

A unique pair of GATC specific DNA methyltransferases in Mitsuokella multiacida.

Two GATC specific methylases together with Sau3AI isoschizomeric restriction endonuclease were partially characterized in Mitsuokella multiacida 46/5. This is the first report on the presence of solitary Dam methyltransferase alongside GATC specific restriction-modification system resulting in the unusual two-fold methylation of the GATC motifs.

Bacteroidaceae↗

PubMed2004

Different restriction and modification phenotypes in ruminal lactate-utilizing bacteria.

Analysis of restriction and modification activities in lactate-utilizing bacteria belonging to the Megasphaera elsdenii and Mitsuokella multiacida species revealed the presence of GATC-specific, MboI isospecific, restriction-modification (R-M) systems in all strains tested. While restriction endonucleases isolated from M. elsdenii strains were found to be sensitive to Dam methylation, enzymes from M. multiacida cleaved DNA irrespective of Dam methylation. The comparison of type II R-M systems specificities in three closely related lactate-utilizing ruminal bacterial species indicated complete lack of restriction and/or modification enzymes previously characterized from Selenomonas ruminantium in tested M. elsdenii and M. multiacida strains. R-M systems are believed to represent the main defense tool against phage infection. Based on the results of our experiments it could be assumed that M. elsdenii and M. multiacida use the different strategy for bacteriophage protection compared to S. ruminantium.

Animals↗