▁grouping ▁is ▁as ▁yet ▁unclear . ▁ ▁The ▁un ifying ▁feature ▁of ▁the ▁T A LE - lik es ▁are ▁their ▁tan dem ▁arrays ▁of ▁DNA ▁binding ▁repe ats . ▁These ▁repe ats ▁are , ▁with ▁few ▁exceptions , ▁ 3 3 - 3 5 ▁am ino ▁ac ids ▁in ▁length , ▁and ▁composed ▁of ▁two ▁alpha - hel ices ▁on ▁either ▁side ▁of ▁a ▁flexible ▁loop ▁containing ▁the ▁DNA ▁base ▁binding ▁resid ues ▁and ▁with ▁neighbour ing ▁repe ats ▁joined ▁by ▁flexible ▁linker ▁loops . ▁Ev idence ▁for ▁this ▁common ▁structure ▁comes ▁in ▁part ▁from ▁solved ▁cry stal ▁structures ▁of ▁T A LE s ▁ ▁and ▁a ▁Bur k holder ia ▁T A LE - like ▁( B AT ), ▁but ▁also ▁from ▁the ▁conservation ▁of ▁the ▁code ▁that ▁all ▁T A LE - lik es ▁use ▁to ▁recogn ise ▁DNA - sequ ences . ▁In ▁fact , ▁T A LE , ▁R ip T AL , ▁and ▁B AT ▁repe ats ▁can ▁be ▁mixed ▁and ▁matched ▁to ▁generate ▁functional ▁DNA - binding ▁prote ins ▁with ▁varying ▁aff inity . ▁ ▁T A LE s ▁ ▁T A LE s ▁are ▁the ▁first ▁identified , ▁best - stud ied ▁and ▁largest ▁group ▁within ▁the ▁T A LE - lik es . ▁T A LE s ▁are ▁found ▁throughout ▁the ▁b acter ial ▁genus ▁X anth omon as , ▁compr ising ▁mostly ▁plant ▁path og ens . ▁Those ▁T A LE s ▁which ▁have ▁been ▁studied ▁have ▁all ▁been ▁shown ▁to ▁be ▁secret