Schematic representation of the 11 human Fanconi anemia proteins. The relative sizes of the FA proteins are shown to scale. The FANCF and FANCL proteins are the smallest, and the FANCM and FANCD1/BRCA2 proteins are the largest. The only FA proteins with known enzymatic activity are FANCJ (helicase), FANCM (DNA translocase), and FANCL (E3 ubiquitin ligase). FANCD2 and FANCD1/BRCA2 have been shown to have direct DNA binding activity. dsDNA indicates double strand DNA; HD, helical domain; NES, nuclear export sequences; NLS, nuclear localization signals; OB, oligonucleotide/oligosaccharide-binding folds; ssDNA, single-strand DNA; TD, tower domain; TPR, tetratricopeptide repeat.