Unrooted phylogeny of the Fpg/Nei family. Numbers associated with edges indicate bootstrap support percentages, whereas numbers associated with terminal nodes are GenBank identifiers. Ellipses enclose bacterial clades, the triangle encloses the plant/fungi clade, and the rectangle encloses sequences here designated Nei or NEIL. Dha and Bth represent Desulfitobacterium hafniense and Bacteroides thetaiotaomicron, respectively. GenBank accession nos. are as follows: Desulfitobacterium hafniense (23111783, 23113033, 23113370, and 23117013) and Bacteroides thetaiotaomicron VPI-5482 (29347769 and 29349896).