Before revision: 5,3509,2014) here it is shown that direct recognition between homologous dsDNA is possible through formation of short quadruplexes by complementary hydrogen bonding of the major grooves .
After revision: 5,3509,2014) here it is shown that direct recognition between homologous dsDNA is possible through formation of short quadruplexes by complementary hydrogen bonding of major groove surfaces in parallel alignment .