▁B - D NA ▁with ▁the ▁C - term inal ▁recognition ▁hel ix ▁align ing ▁in ▁the ▁DNA ' s ▁major ▁gro ove ▁and ▁the ▁un struct ured ▁pe pt ide ▁" tail " ▁at ▁the ▁N - ter minus ▁align ing ▁in ▁the ▁minor ▁gro ove . ▁The ▁recognition ▁hel ix ▁and ▁the ▁inter - hel ix ▁loops ▁are ▁rich ▁in ▁arg in ine ▁and ▁l ys ine ▁resid ues , ▁which ▁form ▁hydro gen ▁b onds ▁to ▁the ▁DNA ▁back bone . ▁Con ser ved ▁hydro ph ob ic ▁resid ues ▁in ▁the ▁center ▁of ▁the ▁recognition ▁hel ix ▁aid ▁in ▁stabil izing ▁the ▁hel ix ▁pack ing . ▁Home od om ain ▁prote ins ▁show ▁a ▁preference ▁for ▁the ▁DNA ▁sequence ▁ 5 '- TA AT - 3 '; ▁sequence - in dependent ▁binding ▁occurs ▁with ▁significantly ▁lower ▁aff inity . ▁The ▁specific ity ▁of ▁a ▁single ▁home od om ain ▁protein ▁is ▁usually ▁not ▁enough ▁to ▁recognize ▁specific ▁target ▁gene ▁prom ot ers , ▁making ▁c of actor ▁binding ▁an ▁important ▁mechanism ▁for ▁cont rolling ▁binding ▁sequence ▁specific ity ▁and ▁target ▁gene ▁expression . ▁To ▁achieve ▁higher ▁target ▁specific ity , ▁home od om ain ▁prote ins ▁form ▁complex es ▁with ▁other ▁trans cription ▁factors ▁to ▁recognize ▁the ▁prom oter ▁region ▁of ▁a ▁specific ▁target ▁gene . ▁ ▁Bi ological ▁function ▁ ▁Home od om ain ▁prote ins ▁function ▁as ▁trans cription ▁factors ▁due ▁to ▁the ▁DNA ▁binding ▁properties ▁of ▁the ▁conser ved ▁HT H ▁mot if . ▁Home