scholarly journals Conformational Complexity in the LH2 Antenna of the Purple Sulfur Bacterium Allochromatium vinosum Revealed by Hole-Burning Spectroscopy

2017 ◽  
Vol 121 (23) ◽  
pp. 4435-4446 ◽  
Author(s):  
Adam Kell ◽  
Mahboobe Jassas ◽  
Khem Acharya ◽  
Kirsty Hacking ◽  
Richard J. Cogdell ◽  
...  
2010 ◽  
Vol 192 (24) ◽  
pp. 6369-6377 ◽  
Author(s):  
Fabian Grein ◽  
Inês A. C. Pereira ◽  
Christiane Dahl

ABSTRACT The DsrMKJOP transmembrane complex has a most important function in dissimilatory sulfur metabolism and consists of cytoplasmic, periplasmic, and membrane integral proteins carrying FeS centers and b- and c-type cytochromes as cofactors. In this study, the complex was isolated from the purple sulfur bacterium Allochromatium vinosum and individual components were characterized as recombinant proteins. The two integral membrane proteins DsrM and DsrP were successfully produced in Escherichia coli C43(DE3) and C41(DE3), respectively. DsrM was identified as a diheme cytochrome b, and the two hemes were found to be in low-spin state. Their midpoint redox potentials were determined to be +60 and +110 mV. Although no hemes were predicted for DsrP, it was also clearly identified as a b-type cytochrome. To the best of our knowledge, this is the first time that heme binding has been experimentally proven for a member of the NrfD protein family. Both cytochromes were partly reduced after addition of a menaquinol analogue, suggesting interaction with quinones in vivo. DsrO and DsrK were both experimentally proven to be FeS-containing proteins. In addition, DsrK was shown to be membrane associated, and we propose a monotopic membrane anchoring for this protein. Coelution assays provide support for the proposed interaction of DsrK with the soluble cytoplasmic protein DsrC, which might be its substrate. A model for the function of DsrMKJOP in the purple sulfur bacterium A. vinosum is presented.


2014 ◽  
Vol 70 (10) ◽  
pp. 1424-1427 ◽  
Author(s):  
José A. Brito ◽  
André Gutierres ◽  
Kevin Denkmann ◽  
Christiane Dahl ◽  
Margarida Archer

The ability to perform the very simple oxidation of two molecules of thiosulfate to tetrathionate is widespread among prokaryotes. Despite the prevalent occurrence of tetrathionate formation and its well documented significance within the sulfur cycle, little is known about the enzymes that catalyze the oxidative condensation of two thiosulfate anions. To fill this gap, the thiosulfate dehydrogenase (TsdA) enzyme from the purple sulfur bacteriumAllochromatium vinosumwas recombinantly expressed inEscherichia coli, purified and crystallized, and a crystallographic data set was collected. The crystals belonged to the monoclinic space groupC2, with unit-cell parametersa= 79.2,b= 69.9,c= 57.9 Å, β = 129.3°, contained one monomer per asymmetric unit and diffracted to a resolution of 1.98 Å.


PLoS ONE ◽  
2012 ◽  
Vol 7 (7) ◽  
pp. e40785 ◽  
Author(s):  
Yvonne Stockdreher ◽  
Sofia S. Venceslau ◽  
Michaele Josten ◽  
Hans-Georg Sahl ◽  
Inês A. C. Pereira ◽  
...  

2017 ◽  
Vol 121 (43) ◽  
pp. 9999-10006 ◽  
Author(s):  
Adam Kell ◽  
Mahboobe Jassas ◽  
Kirsty Hacking ◽  
Richard J. Cogdell ◽  
Ryszard Jankowiak

2014 ◽  
Vol 80 (7) ◽  
pp. 2279-2292 ◽  
Author(s):  
Thomas Weissgerber ◽  
Marc Sylvester ◽  
Lena Kröninger ◽  
Christiane Dahl

ABSTRACTIn the present study, we compared the proteome response ofAllochromatium vinosumwhen growing photoautotrophically in the presence of sulfide, thiosulfate, and elemental sulfur with the proteome response when the organism was growing photoheterotrophically on malate. Applying tandem mass tag analysis as well as two-dimensional (2D) PAGE, we detected 1,955 of the 3,302 predicted proteins by identification of at least two peptides (59.2%) and quantified 1,848 of the identified proteins. Altered relative protein amounts (≥1.5-fold) were observed for 385 proteins, corresponding to 20.8% of the quantifiedA. vinosumproteome. A significant number of the proteins exhibiting strongly enhanced relative protein levels in the presence of reduced sulfur compounds are well documented essential players during oxidative sulfur metabolism, e.g., the dissimilatory sulfite reductase DsrAB. Changes in protein levels generally matched those observed for the respective relative mRNA levels in a previous study and allowed identification of new genes/proteins participating in oxidative sulfur metabolism. One gene cluster (hyd; Alvin_2036-Alvin_2040) and one hypothetical protein (Alvin_2107) exhibiting strong responses on both the transcriptome and proteome levels were chosen for gene inactivation and phenotypic analyses of the respective mutant strains, which verified the importance of the so-called Isp hydrogenase supercomplex for efficient oxidation of sulfide and a crucial role of Alvin_2107 for the oxidation of sulfur stored in sulfur globules to sulfite. In addition, we analyzed the sulfur globule proteome and identified a new sulfur globule protein (SgpD; Alvin_2515).


Marine Drugs ◽  
2018 ◽  
Vol 16 (8) ◽  
pp. 270
Author(s):  
Johannes Imhoff ◽  
Mingshuang Sun ◽  
Jutta Wiese ◽  
Marcus Tank ◽  
Axel Zeeck

The production of secondary metabolites by a new isolate of the purple sulfur bacterium Allochromatium vinosum, which had shown antibiotic activities during a preliminary study, revealed the production of several metabolites. Growth conditions suitable for the production of one of the compounds shown in the metabolite profile were established and compound 1 was purified. The molecular formula of compound 1 (C20H28O2) was determined by high resolution mass spectra, and its chemical structure by means of spectroscopic methods. The evaluation of these data revealed that the structure of the compound was identical to dehydroabietic acid, a compound known to be characteristically produced by conifer trees, but so far not known from bacteria, except cyanobacteria. The purified substance showed weak antibiotic activities against Bacillus subtilis and Staphylococcus lentus with IC50 values of 70.5 µM (±2.9) and 57.0 µM (±3.3), respectively.


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