..._1626, Acel_1628, Acel_1634, Acel_1639, Acel_1643, and Acel_1644) encode proteins that bear highest sequence similarity
to proteins from thermophilic bacteria and archaea. With the exception of Acel_1626, homologs of these six proteins do not occur in Frankia . In addition to the three major
islands, 21...