SASDC48: ScsC-ScsBalpha complex (DsbA-like protein, ScsC + Putative metal ...

Basic information

• Entry: Database: SASBDB / ID: SASDC48

Sample

ScsC-ScsBalpha complex

• DsbA-like protein (protein), ScsC, Proteus mirabilis ATCC 29906
• Putative metal resistance protein (protein), ScsB, Proteus mirabilis (strain HI4320)

Function / homology

Function:

cytochrome complex assembly / membrane

Domain/homology:

DsbD gamma / Thiol:disulfide interchange protein DsbD, N-terminal domain / Thiol:disulfide interchange protein DsbD, N-terminal / Cytochrome C biogenesis protein, transmembrane domain / Cytochrome C biogenesis protein transmembrane region / Thioredoxin, conserved site / Thioredoxin family active site. / Thioredoxin-like superfamily

Component:

Putative metal resistance protein / :

• Biological species: Proteus mirabilis ATCC 29906 (bacteria); Proteus mirabilis (strain HI4320) (bacteria)
• Citation: Journal: J Biol Chem / Year: 2018; Title: Disulfide isomerase activity of the dynamic, trimeric ScsC protein is primed by the tandem immunoglobulin-fold domain of ScsB.; Authors: Emily J Furlong / Hassanul G Choudhury / Fabian Kurth / Anthony P Duff / Andrew E Whitten / Jennifer L Martin / ; Abstract: Correct disulfide bond formation is essential for proper folding of many proteins, including bacterial virulence factors. The suppressor of copper sensitivity (Scs) proteins have roles in dithiol/disulfide interchange and the bacterial response to copper stress. Encoded in a four-gene cassette (ScsABCD) present in many Gram-negative bacteria, the Scs proteins are enigmatic and poorly characterized. Here, we show that the periplasmic α-domain of the membrane protein ScsB in the Gram-negative bacterium forms a redox relay with the soluble periplasmic protein PmScsC. We also found that the periplasmic α-domain is sufficient to activate the disulfide isomerase activity of PmScsC. The crystal structure of PmScsBα at a resolution of 1.54 Å revealed that it comprises two structurally similar immunoglobulin-like folds, one of which includes a putative redox-active site with the sequence CC. We confirmed the importance of these cysteine residues for PmScsBα function, and in addition, we engineered cysteine variants that produced a stable complex between PmScsC and PmScsBα. Using small-angle X-ray and neutron scattering analyses with contrast variation, we determined a low-resolution structure of the PmScsC-PmScsBα complex. The structural model of this complex suggested that PmScsBα uses both of its immunoglobulin-like folds to interact with PmScsC and revealed that the highly dynamic PmScsC becomes ordered upon PmScsBα binding. These findings add to our understanding of the poorly characterized Scs proteins.

Contact author

• Andrew Whitten (ANSTO, Australian Nuclear Science and Technology Organisation, Kirrawee DC, NSW 2232, Australia)

Models

• Model #1599: ; Type: atomic / Software: (7.d) / Radius of dummy atoms: 1.90 A / Symmetry: P1; Comment: Overall symmetry is P1, but the ScsC component possesses P3 symmetry; Chi-square value: 1.7956; Search similar-shape structures of this assembly by Omokage search (details)

Sample

• Sample: Name: ScsC-ScsBalpha complex / Specimen concentration: 0.56-4.50 / Entity id: 820 / 821
• Buffer: Name: 10mM HEPES, 150mM NaCl / pH: 7.5

Entity #820

Name: ScsC / Type: protein / Description: DsbA-like protein / Formula weight: 24.768 / Num. of mol.: 3 / Source: Proteus mirabilis ATCC 29906 / References: UniProt: C2LPE2
Sequence:

SNAALNAAQE KEVRALVRDT LVSNPEILEE AIMALQTKKA DEQQAQFRQA LASEHDALYN DAASPRIGAK DAKLVLVSFT DYNCPYCKRF DPLLEKITEQ YPDVAVIIKP LPFKGESSAK ASQAVLSVWK EDPKAFLALH QRLMQKKTML DNASIEDAMK STNTSKIKLT DDSLKTLQNN LELSRKLGIQ GTPATVIGDT ILPGAVDYDQ LEIIVKEQLA KVKK

Entity #821

Name: ScsB / Type: protein / Description: Putative metal resistance protein / Formula weight: 30.343 / Num. of mol.: 1 / Source: Proteus mirabilis (strain HI4320) / References: UniProt: B4EV20
Sequence:

MHHHHHHSSG VDLGTENLYF QSNADTGWLT MPDNDHAQVR ATADKSSTGD VKILLEVQLA PGWKTYWRSP GEGGVAPEIN WTQSVSDMIW HWPSPSAFDV AGIHTQGYDK EVVFPIELKS VDSDNLNGVL TLSTCSNVCI LTDYSLNLDL NEPAPADFEW QYNQAMAKVP VTSGLISAVS SDYRNSQLTL SLQREQGDWH QPNIYLDPPQ GMLYGIPQLT AKGDHLSVTV DVTDDWGDAA GDITGKALSF VVTDDGYSRQ VNDTIGQGDS ASLPTADS

Experimental information

• Beam: Instrument name: Australian Synchrotron SAXS/WAXS / City: Melbourne / 国: Australia / Shape: Point / Type of source: X-ray synchrotron / Wavelength: 0.1033 Å / Dist. spec. to detc.: 2.68 mm
• Detector: Name: Pilatus 1M / Type: Dectris / Pixsize x: 172 mm

Scan

Title: ScsC-ScsBalpha complex / Measurement date: Nov 2, 2016 / Storage temperature: 4 °C / Cell temperature: 10 °C / Exposure time: 1 sec. / Number of frames: 13 / Unit: 1/A /

	Min	Max
Q	0.0105	0.2999

Distance distribution function P(R)

Sofotware P(R): GNOM 4.6 / Number of points: 372 /

	Min	Max
Q	0.01054	0.2999
P(R) point	1	372
R	0	115

Result

Type of curve: single_conc

	Experimental	Standard	Standard error	Porod
MW	95 kDa	95 kDa	5	119 kDa
Volume	-	-	-	145 nm3

	P(R)	P(R) error	Guinier	Guinier error
Forward scattering, I0	0.04026	0.0001	0.04057	0.00012
Radius of gyration, Rg	3.87 nm	0.01	3.92 nm	0.02

	Min	Max	Error
D	-	11.5	3
Guinier point	1	30	-