A four amino acid consensus, -D-E-A-D- (Asp-Glu-Ala-Asp), that resembles an ATP binding site of the Walker B type. DEAD-box helicases are a family of ATP-dependent DNA or RNA helicases belonging to the second superfamily of helicases (SFII), the DExD/H-box RNA helicases (see DEAH-box proteins). They are important in RNA metabolism in both eukaryotes and prokaryotes and may have important functions in mediating microbial pathogenesis. Humans have 36 putative DEAD-box helicases including p68, a nuclear protein involved in cell growth. DEAD proteins have multiple DEAD motifs, and several hundreds of these proteins can be identified in databases. Not all have helicase activity and it may be that their role is to alter the conformation of RNA, thus regulating its binding interaction with proteins.
Subjects: Medicine and Health — Chemistry.