共查询到20条相似文献,搜索用时 0 毫秒
1.
2.
3.
4.
Yajing Liang Zengqiang Gao Fei Wang Yangli Zhang Yuhui Dong Quansheng Liu 《The Journal of biological chemistry》2014,289(30):21191-21202
Toxin YafQ functions as a ribonuclease in the dinJ-yafQ toxin-antitoxin system of Escherichia coli. Antitoxin DinJ neutralizes YafQ-mediated toxicity by forming a stable protein complex. Here, crystal structures of the (DinJ)2-(YafQ)2 complex and the isolated YafQ toxin have been determined. The structure of the heterotetrameric complex (DinJ)2-(YafQ)2 revealed that the N-terminal region of DinJ folds into a ribbon-helix-helix motif and dimerizes for DNA recognition, and the C-terminal portion of each DinJ exclusively wraps around a YafQ molecule. Upon incorporation into the heterotetrameric complex, a conformational change of YafQ in close proximity to the catalytic site of the typical microbial ribonuclease fold was observed and validated. Mutagenesis experiments revealed that a DinJ mutant restored YafQ RNase activity in a tetramer complex in vitro but not in vivo. An electrophoretic mobility shift assay showed that one of the palindromic sequences present in the upstream intergenic region of DinJ served as a binding sequences for both the DinJ-YafQ complex and the antitoxin DinJ alone. Based on structure-guided and site-directed mutagenesis of DinJ-YafQ, we showed that two pairs of amino acids in DinJ were important for DNA binding; the R8A and K16A substitutions and the S31A and R35A substitutions in DinJ abolished the DNA binding ability of the DinJ-YafQ complex. 相似文献
5.
6.
7.
8.
9.
10.
11.
12.
Obolbek Turapov Simon J. Waddell Bernard Burke Sarah Glenn Asel A. Sarybaeva Griselda Tudo Gilles Labesse Danielle I. Young Michael Young Peter W. Andrew Philip D. Butcher Martin Cohen-Gonsaud Galina V. Mukamolova 《The Journal of biological chemistry》2014,289(36):25241-25249
We have recently shown that RaaS (regulator of antimicrobial-assisted survival), encoded by Rv1219c in Mycobacterium tuberculosis and by bcg_1279c in Mycobacterium bovis bacillus Calmette-Guérin, plays an important role in mycobacterial survival in prolonged stationary phase and during murine infection. Here, we demonstrate that long chain acyl-CoA derivatives (oleoyl-CoA and, to lesser extent, palmitoyl-CoA) modulate RaaS binding to DNA and expression of the downstream genes that encode ATP-dependent efflux pumps. Moreover, exogenously added oleic acid influences RaaS-mediated mycobacterial improvement of survival and expression of the RaaS regulon. Our data suggest that long chain acyl-CoA derivatives serve as biological indicators of the bacterial metabolic state. Dysregulation of efflux pumps can be used to eliminate non-growing mycobacteria. 相似文献
13.
14.
15.
16.
Maryam Khodai-Kalaki Daniel F. Aubert Miguel A. Valvano 《The Journal of biological chemistry》2013,288(42):30473-30484
AtsR is a membrane-bound hybrid sensor kinase of Burkholderia cenocepacia that negatively regulates quorum sensing and virulence factors such as biofilm production, type 6-secretion, and protease secretion. Here we elucidate the mechanism of AtsR phosphorelay by site-directed mutagenesis of predicted histidine and aspartic acid phosphoacceptor residues. We demonstrate by in vitro phosphorylation that histidine 245 and aspartic acid 536 are conserved sites of phosphorylation in AtsR, and we also identify the cytosolic response regulator AtsT (BCAM0381) as a key component of the AtsR phosphorelay pathway. Monitoring the function of AtsR and its derivatives in vivo by measuring extracellular protease activity and swarming motility confirmed the in vitro phosphorylation results. Together we find that the AtsR receiver domain plays a fine-tuning role in determining the levels of phosphotransfer from its sensor kinase domain to the AtsT response regulator. 相似文献
17.
18.
Torsten Hartmann Bo Zhang Grégory Baronian Bettina Schulthess Dagmar Homerova Stephanie Grubmüller Erika Kutzner Rosmarie Gaupp Ralph Bertram Robert Powers Wolfgang Eisenreich Jan Kormanec Mathias Herrmann Virginie Molle Greg A. Somerville Markus Bischoff 《The Journal of biological chemistry》2013,288(50):36116-36128