NMR structure of the N‐terminal‐most HRDC1 domain of RecQ helicase from Deinococcus radiodurans

Abstract

Edited by Christian GriesingerKeywords: DrRecQ HRDC1 NMR Structure DNA a b s t r a c tThe RecQ helicase from Deinococcus radiodurans (DrRecQ) distinguishes from other helicases in that it utilizes its three 'helicase and RNaseD C-terminal' domains (HRDC1, HRDC2 and HRDC3) to regulate its activity. These HRDC domains have different influence on the biochemical functions of DrRecQ. Currently, only the structure of HRDC3 was reported. Here, we determined the NMR structure of the N-terminal-most HRDC1, revealing a potential DNA binding domain. Fluorescence anisotropy assay indicates that HRDC1 has binding affinity weaker than 70 lM to all DNA substrates without any specificity. Biochemical assays suggested that HRDC1 cooperates with other domains to enhance full-length DrRecQ interactions with DNA.

Structural mechanisms of human RecQ helicases WRN and BLM

“…Recent advances in the structural studies of WRN and BLM, in particular the discovery of the “DNA zip-slider” function of the RQC domain to catalyze strand separation, have greatly improved our understanding of WRN and BLM in terms of their preferential activities toward recombination and repair intermediates. In this paper, I have focused on the structures of WRN and BLM, but it should be mentioned that other important RecQ structures that could not be discussed here are also available, including those of Escherichia coli RecQ ( Bernstein et al, 2003 ; Bernstein and Keck, 2005 ), Deinococcus radiodurans RecQ ( Killoran and Keck, 2008 ; Liu et al, 2013 ) and human RECQ1 (a protein that is not associated with genetic disease; Pike et al, 2009 ). The structure of E. coli RecQ without DNA ( Bernstein et al, 2003 ) gave us the first structural image of the RecQ-family helicase core, although recent data imply that the β-wing of bacterial RecQs is not involved in DNA unwinding ( Pike et al, 2009 ; Hoadley and Keck, 2010 ).…”

Crystal Structure ofDeinococcus radioduransRecQ Helicase Catalytic Core Domain: The Interdomain Flexibility

“…The helicase catalytic core is crucial for the ATPase and DNA-unwinding activities of these RecQ proteins. The HRDC domain is responsible for regulating DNA-binding affinity with a wide variety of DNA substrates [5]. To date, tertiary structures of the RecQ helicase catalytic core have been reported and determined by X-ray crystallography, including those of E. coli RecQ (PDB 1OYW) and human RecQ1 (hRecQ1) (PDB 2V1X) [4, 6].…”

“…The function of DrRecQ has been characterized, confirming that the unusual domain arrangement of DrRecQ has the extraordinary ability to repair DNA damage in D. radiodurans [10]. HRDC1 and HRDC3 have also been structurally characterized [5, 11]. However, the structure of the helicase catalytic core remains undetermined.…”

A Nucleotide-dependent and HRDC Domain-dependent Structural Transition in DNA-bound RecQ Helicase

“…Due to its flexible linkage to the helicase motor core, the HRDC domain could not be crystallized with the other RecQ domains. Thus, its structure has been determined in isolation from other parts of the molecule (35,37,38). This domain was found to be necessary for the processing of complex DNA structures in human BLM and E. coli RecQ (28,39).…”