Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:6.2.1.7 (BAL)
 1,977 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The lipid-containing bacteriophage PR4 is of special intest because it can replicate in various gram-negative bacteria, including Escherichia coli, that carry one of a group of drug resistance plasmids. PR4 grown in E. coli strain PS2R contains about 10% lipid by weight, with the negatively charged phospholipid phosphatidylglycerol being the most abundant lipid in the virion. We now report the following. (i) PR4 attaches to E. coli with an attachment rate constant of Ka approximately 6.2 X 10(-10) ml/min, which is about twice that of the enveloped phage phi6 (to Pseudomonas phaseolicola), but a factor of 5 less than that of phage PM2 (to Pseudomonas BAL-31). (ii) Use of an E. coli glycerol auxotroph indicated that a normal amount of PR4 replication occurs only if glycerol starvation (inhibition of all phospholipid synthesis) begins no earlier than about halfway through the lytic cycle. (iii) Use of an E. coli fatty acid synthesis temperature-sensitive mutant and an E. coli phosphatidylethanolamine synthesis temperature-sensitive mutant indicate that PR4 replication can occur in the absence of either normal fatty acid synthesis or normal phospholipid synthesis if the infection takes place prior to the termination of overall cell growth and the onset of cell death, (iv) Whereas PR4 burst size in nutrient media at 30 degrees C to 42%C is about 40, the burst size at 20 degrees C is less than 3, Temperature-shift experiments show that the temperature late in infection determines the burst size.
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PMID:Effects of temperature and host cell genetic characteristics on the replication of the lipid-containing bacteriophage PR4 in Escherichia coli. 32 29

Turnover of the acylated and unacylated glycerol moieties of phosphatidylglycerol was examined during infection of Pseudomonas BAL-31 by bacteriophage PM2. No turnover of either glycerol moiety was observed in infected or inunfected cells. The stereochemical configuration of phosphatidylglycerol from both virus and host was determined and proved to be 3-sn-phosphatidyl-1'-sn-glycerol. These results exclude a mechanism of mobilizing lipids for the virus by acylation and deacylation of 3-sn-phosphatidyl-1'-sn-glycerol in the host membrane to form 1-sn-phosphatidyl-3'-sn-glycerol in the membrane of PM2.
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PMID:Stereoconfiguration of phosphatidylglycerol in the membrane of bacteriophage PM2 and in its host, Pseudomonas BAL-31. 63 77

Infection of Pseudomonas BAL-31 with the lipid-containing bacteriophage PM2 resulted in no detectable change in the rate of phosphatidylglycerol (PG) or phosphatidylethanolamine (PE) biosynthesis. An increase in the PG content of infected cultures was not seen until the cultures began to lyse, and this increase was in fact only a relative increase resulting from the extensive turnover of PE at the onset of culture lysis. Turnover studies revealed that the glycerol, phosphorus fatty acid, and ethanolamine moieties of PE turned over simultaneously at the time of lysis, and therefore made it unlikely that there was a PE to PG conversion during the latent period of the phage. The lipid found in the bacteriophage did not reflect a preferential selection for lipid synthesized before or after infection, but in fact reflected the composition of the host membrane at the time the phage were assembled. The use of a modified medium that allowed the cultivation of Pseudomonas BAL-31 as a prototroph and resulted in reliable lysis times of infected cultures led us to the conclusion that PM2 infection effects little change in host phospholipid metabolism, and that there is sufficient PG in the host cytoplasmic membrane to account for a full burst of phage. As a result of the reliable lysis times that we have achieved, we concluded that certain metabolic events, i.e., PE turnover, are lytic phenomena and must not be confused with events relevant to the biosynthesis and maturation of the phage.
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PMID:Phospholipid metabolism in Pseudomonas BAL-31 infected with lipid-containing bacteriophage PM2. 95 79

Compound X, a minor phospholipid of Pseudomonas BAL-31 and bacteriophage PM2, has been identified as X-3-phosphatidyl-1'-(3'-acyl)-glycerol, or acyl phosphatidylglycerol. The water-soluble product obtained by mild alkaline hydrolysis showed the same RF value as that of glycerophosphoryl-glycerol. The chemical analysis gave the ratio 1 : 3 : 2 for phosphate-acyl ester-glycerol. The position of the third acyl group was determined by nuclear magnetic resonance techniques.
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PMID:Identification of acyl phosphatidylglycerol as a minor phospholipid of Pseudomonas BAL-31. 99 Feb 98

DNA fragments from Pseudomonas aeruginosa carrying the PaeR7 restriction/modification genes have been cloned in the plasmid vector pBR322 and propagated in Escherichia coli. A subclone (pPAORM3.8) has been constructed that contains the complete restriction/modification system on a 3.8-kilobase DNA fragment. Digestion of the pPAORM3.8 plasmid with nuclease BAL-31 has yielded two types of clones. One type contains an active methylase gene but no active endonuclease gene; such clones will modify the DNA but not restrict the growth of incoming phage in vivo. The second type contains an active endonuclease gene but no active methylase gene, as judged both by in vivo tests and by the activity of the cell extracts in vitro. Although extracts of cells containing these plasmids display restriction endonuclease activity, these bacteria are unable to restrict the growth of incoming phage. Furthermore, chromosomal and phage DNA isolated from these host cells are not protected against cleavage by PaeR7 in vitro. The properties of PaeR7 endonuclease and methylase enzymes have also been examined. The PaeR7 restriction endonuclease recognizes and cleaves the sequence C decreased T-C-G-A-G, as does Xho I. However, there exists a canonical Xho I site at 26.5% on the adenovirus 2 genome which is totally refractory to PaeR7 cleavage but is cut by Xho I. Under conditions of low salt, high glycerol, and high enzyme concentrations, a "PaeR7" activity is found that is similar to that observed for EcoRI. Finally, evidence is presented that the PaeR7 methylase modifies the adenine residue within the recognition sequence.
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PMID:Cloned restriction/modification system from Pseudomonas aeruginosa. 630 Aug 41

A deoxyribonucleic acid (DNA)-dependent DNA polymerase (DNA nucleotidyltransferase) was purified 3,000-fold from the marine Pseuodomonas sp. BAL-31. The molecular weight of the native enzyme was estimated by glycerol gradient sedimentation to be 110,000. The enzyme migrated in sodium dodecyl sulfate-acrylamide gels as a single polypeptide with a molecular weight of 105,000. An absolute requirement for divalent cation was satisfied by Mg2+ or Mn2+ at concentrations of 1 mM. Monovalent cations at concentrations higher than 50 mM showed an inhibitory effect. The polymerase activity was resistant to N-ethylmaleimide and showed a wide pH optimum.
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PMID:Deoxyribonucleic acid polymerase from the marine Pseudomonas sp. BAL-31. 737 71