Structural protein of the sulfur globules, which are intracellular globules that serve for sulfur storage in purple sulfur bacteria.

MKIKALALSAVIALSATSAQAFWGGPGYGGGPWSNMWDNNAFGDGFGDFNMNMNARGSGY GRGYNRGYGYGGYPYGGYGAPYGGYGAPYGYGAPYGAVPPMAPMAPAAPAAVAK115

	PMID	Title & Author	Abstract	Year
0	24487535	A comparative quantitative proteomic study identifies new proteins relevant for sulfur oxidation in the purple sulfur bacterium Allochromatium vinosum. Weissgerber T, Sylvester M, Kröninger L, Dahl C.	In the present study, we compared the proteome response of Allochromatium vinosum when 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 quantified A. vinosum proteome. 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).	2014
1	15340792	The role of the sulfur globule proteins of Allochromatium vinosum: mutagenesis of the sulfur globule protein genes and expression studies by real-time RT-PCR. Prange A, Engelhardt H, Trüper HG, Dahl C.	During oxidation of reduced sulfur compounds, the purple sulfur bacterium Allochromatium vinosum stores sulfur in the periplasm in the form of intracellular sulfur globules. The sulfur in the globules is enclosed by a protein envelope that consists of the homologous 10.5-kDa proteins SgpA and SgpB and the smaller 8.5-kDa SgpC. Reporter gene fusions of sgpA and alkaline phosphatase showed the constitutive expression of sgpA in A. vinosum and yielded additional evidence for the periplasmic localization of the sulfur globules. Expression analysis of the wild-type sgp genes by quantitative RT-PCR using the LightCycler system showed the constitutive expression of all three sgp genes. The expression of sgpB and sgpC is significantly enhanced under photolithotrophic conditions. Interestingly, sgpB is expressed ten times less than sgpA and sgpC implying that SgpA and SgpC are the "main proteins" of the sulfur globule envelope. Mutants with inactivated sgpA or sgpB did not show any differences in comparison with the wild-type, i.e., the encoded proteins can replace each other, whereas inactivation of sgpC leads to the formation of considerably smaller sulfur globules. This indicates a role of SgpC for globule expansion. A sgpBC double mutant was unable to grow on sulfide and could not form sulfur globules, showing that the protein envelope is indispensible for the formation and deposition of intracellular sulfur.	2004
2	9560425	Molecular genetic evidence for extracytoplasmic localization of sulfur globules in Chromatium vinosum. Pattaragulwanit K, Brune DC, Trüper HG, Dahl C.	Purple sulfur bacteria store sulfur as intracellular globules enclosed by a protein envelope. We cloned the genes sgpA, sgpB, and sgpC, which encode the three different proteins that constitute the sulfur globule envelope of Chromatium vinosum D (DSMZ 180(T)). Southern hybridization analyses and nucleotide sequencing showed that these three genes are not clustered in the same operon. All three genes are preceded by sequences resembling sigma70-dependent promoters, and hairpin structures typical for rho-independent terminators are found immediately downstream of the translational stop codons of sgpA, sgpB, and sgpC. Insertional inactivation of sgpA in Chr. vinosum showed that the presence of only one of the homologous proteins SgpA and SgpB suffices for formation of intact sulfur globules. All three sgp genes encode translation products which - when compared to the isolated proteins - carry amino-terminal extensions. These extensions meet all requirements for typical signal peptides indicating an extracytoplasmic localization of the sulfur globule proteins. A fusion of the phoA gene to the sequence encoding the proposed signal peptide of sgpA led to high specific alkaline phosphatase activities in Escherichia coli, further supporting the envisaged targeting process. Together with electron microscopic evidence these results provide strong indication for an extracytoplasmic localization of the sulfur globules in Chr. vinosum and probably in other Chromatiaceae. Extracytoplasmic formation of stored sulfur could contribute to the transmembranous Deltap that drives ATP synthesis and reverse electron flow in Chr. vinosum.	1998

Weissgerber, T., Sylvester, M., Kröninger, L., and Dahl, C. (2014) A comparative quantitative proteomic study identifies new proteins relevant for sulfur oxidation in the purple sulfur bacterium Allochromatium vinosum. Appl Environ Microbiol 80: 2279–2292. Prange, A., Engelhardt, H., Trüper, H.G., and Dahl, C. (2004) The role of the sulfur globule proteins of Allochromatium vinosum: mutagenesis of the sulfur globule protein genes and expression studies by real‐time RT‐PCR. Arch Microbiol 182: 165–174.