• Structure of the effector-binding domain of the LysR-type transcription factor RovM from Yersinia pseudotuberculosis.

      Quade, Nick; Dieckmann, Marieke; Haffke, Matthias; Heroven, Ann Kathrin; Dersch, Petra; Heinz, Dirk W; Department of Molecular Structural Biology, Helmholtz Centre for Infection Research, D-38124 Braunschweig, Germany. (2011-02)
      In enteropathogenic Yersinia, the expression of several early-phase virulence factors such as invasin is tightly regulated in response to environmental cues. The responsible regulatory network is complex, involving several regulatory RNAs and proteins such as the LysR-type transcription regulator (LTTR) RovM. In this study, the crystal structure of the effector-binding domain (EBD) of RovM, the first LTTR protein described as being involved in virulence regulation, was determined at a resolution of 2.4 Å. Size-exclusion chromatography and comparison with structures of full-length LTTRs show that RovM is most likely to adopt a tetrameric arrangement with two distant DNA-binding domains (DBDs), causing the DNA to bend around it. Additionally, a cavity was detected in RovM which could bind small inducer molecules.
    • Structures of the nucleotide-binding domain of the human ABCB6 transporter and its complexes with nucleotides.

      Haffke, Matthias; Menzel, Anja; Carius, Yvonne; Jahn, Dieter; Heinz, Dirk W; Helmholtz Zentrum für Infektionsforschung, Braunschweig, Germany. (2010-09)
      The human ATP-binding cassette (ABC) transporter ABCB6 is involved in haem-precursor transport across the mitochondrial membrane. The crystal structure of its nucleotide-binding domain (NBD) has been determined in the apo form and in complexes with ADP, with ADP and Mg(2+) and with ATP at high resolution. The overall structure is L-shaped and consists of two lobes, consistent with other reported NBD structures. Nucleotide binding is mediated by the highly conserved Tyr599 and the Walker A motif, and induces notable structural changes. Structural comparison with other structurally characterized NBDs and full-length ABC transporters gives the first insight into the possible catalytic mechanism of ABCB6 and the role of the N-terminal helix alpha(1) in full-length ABCB6.