TY  - JOUR
A1  - Radu, Laura
A1  - Schoenwetter, Elisabeth
A1  - Braun, Cathy
A1  - Marcoux, Julien
A1  - Koelmel, Wolfgang
A1  - Schmitt, Dominik R.
A1  - Kuper, Jochen
A1  - Cianférani, Sarah
A1  - Egly, Jean M.
A1  - Poterszman, Arnaud
A1  - Kisker, Caroline
T1  - The intricate network between the p34 and p44 subunits is central to the activity of the transcription/DNA repair factor TFIIH
JF  - Nucleic Acids Research
N2  - The general transcription factor IIH (TFIIH) is a multi-protein complex and its 10 subunits are engaged in an intricate protein–protein interaction network critical for the regulation of its transcription and DNA repair activities that are so far little understood on a molecular level. In this study, we focused on the p44 and the p34 subunits, which are central for the structural integrity of core-TFIIH. We solved crystal structures of a complex formed by the p34 N-terminal vWA and p44 C-terminal zinc binding domains from Chaetomium thermophilum and from Homo sapiens. Intriguingly, our functional analyses clearly revealed the presence of a second interface located in the C-terminal zinc binding region of p34, which can rescue a disrupted interaction between the p34 vWA and the p44 RING domain. In addition, we demonstrate that the C-terminal zinc binding domain of p34 assumes a central role with respect to the stability and function of TFIIH. Our data reveal a redundant interaction network within core-TFIIH, which may serve to minimize the susceptibility to mutational impairment. This provides first insights why so far no mutations in the p34 or p44 TFIIH-core subunits have been identified that would lead to the hallmark nucleotide excision repair syndromes xeroderma pigmentosum or trichothiodystrophy.
KW  - general transcription factor IIH (TFIIH)
KW  - DNA repair
KW  - protein–protein interaction
KW  - p44
KW  - p34
Y1  - 2017
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-170173
VL  - 45
IS  - 18
ER  - 
TY  - JOUR
A1  - Kaiser, Sebastian
A1  - Sauer, Florian
A1  - Kisker, Caroline
T1  - The structural and functional characterization of human RecQ4 reveals insights into its helicase mechanism
JF  - Nature Communications
N2  - RecQ4 is a member of the RecQ helicase family, an evolutionarily conserved class of enzymes, dedicated to preserving genomic integrity by operating in telomere maintenance, DNA repair and replication. While reduced RecQ4 activity is associated with cancer predisposition and premature aging, RecQ4 upregulation is related to carcinogenesis and metastasis. Within the RecQ family, RecQ4 assumes an exceptional position, lacking several characteristic RecQ domains. Here we present the crystal structure of human RecQ4, encompassing the conserved ATPase core and a novel C-terminal domain that lacks resemblance to the RQC domain observed in other RecQ helicases. The new domain features a zinc-binding site and two distinct types of winged-helix domains, which are not involved in canonical DNA binding or helicase activity. Based on our structural and functional analysis, we propose that RecQ4 exerts a helicase mechanism, which may be more closely related to bacterial RecQ helicases than to its human family members.
KW  - x-ray crystallography
KW  - enzymes
KW  - RecQ4
KW  - humans
Y1  - 2017
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-170769
VL  - 8
IS  - 15907
ER  - 
TY  - JOUR
A1  - Fischer, Annette
A1  - Harrison, Kelly S
A1  - Ramirez, Yesid
A1  - Auer, Daniela
A1  - Chowdhury, Suvagata Roy
A1  - Prusty, Bhupesh K
A1  - Sauer, Florian
A1  - Dimond, Zoe
A1  - Kisker, Caroline
A1  - Hefty, P Scott
A1  - Rudel, Thomas
T1  - Chlamydia trachomatis-containing vacuole serves as deubiquitination platform to stabilize Mcl-1 and to interfere with host defense
JF  - eLife
N2  - Obligate intracellular Chlamydia trachomatis replicate in a membrane-bound vacuole called inclusion, which serves as a signaling interface with the host cell. Here, we show that the chlamydial deubiquitinating enzyme (Cdu) 1 localizes in the inclusion membrane and faces the cytosol with the active deubiquitinating enzyme domain. The structure of this domain revealed high similarity to mammalian deubiquitinases with a unique α-helix close to the substrate-binding pocket. We identified the apoptosis regulator Mcl-1 as a target that interacts with Cdu1 and is stabilized by deubiquitination at the chlamydial inclusion. A chlamydial transposon insertion mutant in the Cdu1-encoding gene exhibited increased Mcl-1 and inclusion ubiquitination and reduced Mcl-1 stabilization. Additionally, inactivation of Cdu1 led to increased sensitivity of C. trachomatis for IFNγ and impaired infection in mice. Thus, the chlamydial inclusion serves as an enriched site for a deubiquitinating activity exerting a function in selective stabilization of host proteins and protection from host defense.
KW  - cell-autonomous defense
KW  - Chlamydia trachomatis
KW  - deubiquitinase
KW  - Mcl-1
Y1  - 2017
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-171073
VL  - 6
IS  - e21465
ER  -