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DNA sequences required to induce localized conversion in Streptococcus pneumoniae transformation

✍ Scribed by Garcia, Pedro ;Gasc, Anne-Marie ;Kyriakidis, Xenophon ;Baty, Daniel ;Sicard, Michel


Publisher
Springer
Year
1988
Tongue
English
Weight
525 KB
Volume
214
Category
Article
ISSN
0026-8925

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✦ Synopsis


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.