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Enzymatic activities leading to pyrimidine nucleotide biosynthesis from cell-free extracts of Rickettsia typhi
- Source :
- Infection and Immunity. 14:439-448
- Publication Year :
- 1976
- Publisher :
- American Society for Microbiology, 1976.
-
Abstract
- Cell-free extracts from Rickettsia typhi were examined for the presence or absence of pyrimidine phosphotransferase enzymes and compared with the enzymes of mouse L cells and Salmonella typhimurium. The organisms were grown in mouse L cells and in the yolk sacs of chicken embryos, purified by Renografin density gradient centrifugation, and ruptured in a French pressure cell. The enzymes for the reutilization of uridine and thymidine, uridine kinase (EC 2.7.1.48) and thymidine kinase (EC 2.7.1.21), were not detected in R. typhi extracts with the phosphate donors effective for control enzymes. The following enzyme activities were demonstrated in R. typhi: uridine-5'-monophosphate kinase (UMPK, EC 2.7.4.4), deoxythymidine-5'-monophosphate kinase (dTMPK, EC 2.7.4.9), and nucleosidediphosphate kinase (NDPK, EC 2.7.4.6). Physicochemical and enzymatic analyses demonstrated that the pyrimidine nucleotide kinases of R. typhi were not of host origin and that the source (yolk sac and mouse L cells) did not influence the relative enzymatic activities. The specific activities of UMPK and dTMPK were higher when the rickettsiae were harvested before embryo death, whereas NDPK levels were slightly decreased. The specific activities of UMPK, dTMPK, and NDPK were comparable to those of S. typhimurium, and consequently the rickettsiae have potential for the anabolism of monophosphates, as do the host-independent bacteria. These results suggest that R. typhi cannot utilize host uridine or thymidine pools directly but must rely on themonophosphorylated molecules of the host cell or must synthesize the monophosphates de novo.
- Subjects :
- Salmonella typhimurium
Time Factors
Immunology
Chick Embryo
Thymidine Kinase
Microbiology
Uridine kinase
Phosphotransferase
Mice
chemistry.chemical_compound
L Cells
Rickettsia typhi
Animals
chemistry.chemical_classification
Cell-Free System
biology
Kinase
Phosphotransferases
biology.organism_classification
Molecular biology
Uridine
Infectious Diseases
Enzyme
chemistry
Biochemistry
Thymidine kinase
Female
Pyrimidine Nucleotides
Uridine Kinase
Parasitology
Thymidine
Vitelline Membrane
Research Article
Subjects
Details
- ISSN :
- 10985522 and 00199567
- Volume :
- 14
- Database :
- OpenAIRE
- Journal :
- Infection and Immunity
- Accession number :
- edsair.doi.dedup.....c6f89582a98a4a3c55bb778819e344fd