Summary
Tranforming pneumococcal DNA is inactivated by treatment with restriction enzymes. For mutations belonging to the same locus (amiA locus), the extent of inactivation depends strongly upon the mutations and the enzymes. Two EcoRI and one BamHI restriction sites have been located within the amiA locus. After treatment of donor DNA with either one of these enzymes, the lowest transforming activity is observed for mutations that map near restriction sites. This effect of proximity to the nearest end of the DNA fragment extends over a distance of 1,400 nucleotides. The curve of transforming activity versus DNA size obtained with endonuclease-generated DNA fragments is very similar to that obtained previously with mechanically sheared DNA. Both curves show a striking slope change for donor DNA size around 2,700 base pairs, i.e. twice the length found for the extent of the ‘end effect’. We suggest that for donor DNA fragments larger than 2,700 base pairs the transforming activity depends mainly upon the size of donor whereas for donor DNA fragments shorter than 2,700 base pairs both a size-dependent phenomenon and the ‘end effect’ contribute to reduce drastically the transforming activity.
References
Cato A, Guild WR (1968) Transformation and DNA size. I. Activity of fragments of defined size and a fit to a random double cross-over model. J Mol Biol 37:157–178
Claverys JP, Lataste H, Sicard AM (1979a) Localization of two EcoRI restriction sites within the amiA locus in pneumococcus: Relationship between the physical and the genetic map. In: Glover SW, Butler LO (eds) Transformation 1978. Costwold Press Ltd, Oxford, pp 161–169
Claverys JP, Lefèvre JC, Sicard AM (1979b) Molecular studies on the marker effect in pneumococcus In: Glover SW, Butler LO (eds) Transformation 1978. Costwold Press Ltd, Oxford, pp 135–150
Claverys JP, Louarn JM, Sicard AM (1981) Cloning of Streptococcus pneumoniae DNA: its use in pneumococcal transformation. Gene 13:65–73
Goodgal SH, Gromkova R (1973) Separation of specific segments of transforming DNA after treatment with endodeoxyribonuclease. Proc Natl Acad Sci USA 70:503–506
Harris-Warrick RM, Elkana Y, Ehrilich SD, Lederberg J (1975) Electrophoretic separation of Bacillus subtilis genes. Proc Natl Acad Sci USA 72:2207–2211
Lacks S (1968) Theoretical relationship between probability of marker integration and length of donor DNA in pneumococcal transformation. J Mol Biol 37:179–180
Lataste H (1980) Utilisation des enzymes de restriction pour l'étude de la transformation bactérienne chez S. pneumoniae. Thèse Université de Toulouse, France
Lataste H, Claverys JP, Sicard AM (1980) Physical and genetic characterization of deletions in Streptococcus pneumoniae. J Bacteriol 144:422–424
Morrison DA, Guild WR (1972) Transformation and deoxyribonucleic acid size: extent of degradation on entry varies with size of donor. J Bacteriol 112:1157–1168
Sicard AM (1964) A new synthetic medium for Diplococcus pneumoniae and its use for the study of reciprocal transformation at the amiA locus. Genetics 50:31–44
Sicard AM, Ephrussi-Taylor H (1965) Genetic recombination in DNA induced transformation of pneumococcus. II. Mapping the amiA region. Genetics 52:1207–1227
Author information
Authors and Affiliations
Additional information
Communicated by K. Isono
Rights and permissions
About this article
Cite this article
Lataste, H., Claverys, JP. & Sicard, A.M. Relation between the transforming activity of a marker and its proximity to the end of the DNA particle. Molec. Gen. Genet. 183, 199–201 (1981). https://doi.org/10.1007/BF00270163
Received:
Issue Date:
DOI: https://doi.org/10.1007/BF00270163