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  - 
TY  - JOUR
A1  - Koelmel, Wolfgang
A1  - Kuper, Jochen
A1  - Kisker, Caroline
T1  - Cesium based phasing of macromolecules: a general easy to use approach for solving the phase problem
JF  - Scientific Reports
N2  - Over the last decades the phase problem in macromolecular x-ray crystallography has become more controllable as methods and approaches have diversified and improved. However, solving the phase problem is still one of the biggest obstacles on the way of successfully determining a crystal structure. To overcome this caveat, we have utilized the anomalous scattering properties of the heavy alkali metal cesium. We investigated the introduction of cesium in form of cesium chloride during the three major steps of protein treatment in crystallography: purification, crystallization, and cryo-protection. We derived a step-wise procedure encompassing a "quick-soak"-only approach and a combined approach of CsCl supplement during purification and cryo-protection. This procedure was successfully applied on two different proteins: (i) Lysozyme and (ii) as a proof of principle, a construct consisting of the PH domain of the TFIIH subunit p62 from Chaetomium thermophilum for de novo structure determination. Usage of CsCl thus provides a versatile, general, easy to use, and low cost phasing strategy.
KW  - structural biology
KW  - X-ray crystallography
Y1  - 2021
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-261644
VL  - 11
IS  - 1
ER  -