Transformation of restriction endonuclease phenotype in Streptococcus pneumoniae
The genetic basis of the unique restriction endonuclease DpnI, that cleaves only at a methylated sequence, 5'-GmeATC-3', and of the complementary endonuclease DpnII, which cleaves at the same sequence when it is not methylated, was investigated. Different strains of Streptococcus pneumoniae isolated from patients contained either DpnI (two isolates) or DpnII (six isolates). The latter strains also contained DNA methylated at the 5'-GATC-3' sequence. A restrictable bacteriophage, HB-3, was used to characterize the various strains and to select for transformants. One laboratory strain contained neither DpnI nor DpnII. It was probably derived from a DpnI-containing strain, and its DNA was not methylated at 5'-GATC-3'. Cells of this strain were transformed to the DpnI restriction phenotype by DNA from a DpnI-containing strain and to the DpnII restriction phenotype by DNA from a DpnII-containing strain. Neither cross-transformation, that is, transformation to one phenotype by DNA from a strain of the other phenotype, nor spontaneous conversion was observed. Extracts of transformants to the new restriction phenotype were shown to contain the corresponding endonuclease.
- Research Organization:
- Brookhaven National Lab., Upton, NY
- OSTI ID:
- 6419738
- Journal Information:
- J. Bacteriol.; (United States), Journal Name: J. Bacteriol.; (United States) Vol. 152:1; ISSN JOBAA
- Country of Publication:
- United States
- Language:
- English
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59 BASIC BIOLOGICAL SCIENCES
BACTERIA
BACTERIOPHAGES
BIOCHEMISTRY
BIOLOGY
CHEMICAL REACTIONS
CHEMISTRY
DATA
DNA
ENZYMES
ESTERASES
EXPERIMENTAL DATA
GENETICS
HYDROLASES
INFORMATION
METHYLATION
MICROORGANISMS
NUCLEASES
NUCLEIC ACIDS
NUMERICAL DATA
ORGANIC COMPOUNDS
PARASITES
PHENOTYPE
PHOSPHODIESTERASES
STREPTOCOCCUS
VIRUSES