Garcia P, Gasc A M, Kyriakidis X, Baty D, Sicard M
Centre de Recherche de Biochimie et Génétique Cellulaires du C.N.R.S., Toulouse, France.
Mol Gen Genet. 1988 Nov;214(3):509-13. doi: 10.1007/BF00330488.
In pneumococcal transformation a particular point mutation belonging to the amiA locus is able markedly to enhance recombination frequency when crossed with any other markers of this gene. This results from a polarized conversion of the mutation towards the wild-type sequence. In this report, by site-directed oligonucleotide mutagenesis, we have generated a series of mutants showing various degrees of conversion. We have found that the substitution 5'-ATTCAT----5'-ATTAAT is a sufficient signal for localized conversion. Changing individual bases within this sequence results in decreased conversion frequencies to levels that depend on the mutation, suggesting that there is a family to related sequences which may act as a substrate for a conversion system. Moreover, the length over which this conversion occurs has been estimated to be 12 base pairs on the average.
