Structure of mycobacterial 3'-to-5' RNA:DNA helicase Lhr bound to a ssDNA tracking strand highlights distinctive features of a novel family of bacterial helicases.

ABSTRACT: Mycobacterial Lhr is a DNA damage-inducible superfamily 2 helicase that uses adenosine triphosphate (ATP) hydrolysis to drive unidirectional 3'-to-5' translocation along single-stranded DNA (ssDNA) and to unwind RNA:DNA duplexes en route. ATPase, translocase and helicase activities are encompassed within the N-terminal 856-amino acid segment. The crystal structure of Lhr-(1-856) in complex with AMPPNP•Mg2+ and ssDNA defines a new helicase family. The enzyme comprises two N-terminal RecA-like modules, a winged helix (WH) domain and a unique C-terminal domain. The 3' ssDNA end binds in a crescent-shaped groove at the interface between the first RecA domain and the WH domain and tracks 5' into a groove between the second RecA and C domains. A kissing interaction between the second RecA and C

SUBMITTER: Ejaz A 

PROVIDER: S-EPMC5758891 | biostudies-literature | 2018 Jan

REPOSITORIES: biostudies-literature