This entry includes archaeal helicases from the helicase superfamily 2, and represents domain 4 described in [1,3]. This domain folds into a seven alpha-helix bundle structure and seems to be unique within this helicase family. The central helix acts as a ratchet and mediates stacking interactions on base moieties of the DNA [3].

1: Structural basis for DNA duplex separation by a superfamily-2 helicase. Buttner K, Nehring S, Hopfner KP; Nat Struct Mol Biol. 2007;14:647-652. PMID:17558417

2: Structure of the DNA repair helicase hel308 reveals DNA binding and autoinhibitory domains. Richards JD, Johnson KA, Liu H, McRobbie AM, McMahon S, Oke M, Carter L, Naismith JH, White MF; J Biol Chem. 2008;283:5118-5126. PMID:18056710

3: Atomic structures and functional implications of the archaeal RecQ-like helicase Hjm. Oyama T, Oka H, Mayanagi K, Shirai T, Matoba K, Fujikane R, Ishino Y, Morikawa K; BMC Struct Biol. 2009;9:2. PMID:19159486