SASDA37: Surface Protein G (SasG) EG5 repeat protein G51-G52

Basic information

• Entry: Database: SASBDB / ID: SASDA37

Sample

Surface Protein G (SasG) EG5 repeat protein G51-G52

• Surface protein G (protein), SasG, Staphylococcus aureus

Function / homology

Function:

single-species submerged biofilm formation / extracellular region

Domain/homology:

E domain / E domain / Bacterial lectin / G5 domain / G5 domain / G5 domain profile. / G5 / YSIRK type signal peptide / YSIRK Gram-positive signal peptide / LPXTG cell wall anchor motif / Gram-positive cocci surface proteins LPxTG motif profile. / LPXTG cell wall anchor domain

Component:

Surface protein G

• Biological species: Staphylococcus aureus (bacteria)
• Citation: Journal: Nat Commun / Year: 2015; Title: Cooperative folding of intrinsically disordered domains drives assembly of a strong elongated protein.; Authors: Dominika T Gruszka / Fiona Whelan / Oliver E Farrance / Herman K H Fung / Emanuele Paci / Cy M Jeffries / Dmitri I Svergun / Clair Baldock / Christoph G Baumann / David J Brockwell / Jennifer R Potts / Jane Clarke / ; Abstract: Bacteria exploit surface proteins to adhere to other bacteria, surfaces and host cells. Such proteins need to project away from the bacterial surface and resist significant mechanical forces. SasG is a protein that forms extended fibrils on the surface of Staphylococcus aureus and promotes host adherence and biofilm formation. Here we show that although monomeric and lacking covalent cross-links, SasG maintains a highly extended conformation in solution. This extension is mediated through obligate folding cooperativity of the intrinsically disordered E domains that couple non-adjacent G5 domains thermodynamically, forming interfaces that are more stable than the domains themselves. Thus, counterintuitively, the elongation of the protein appears to be dependent on the inherent instability of its domains. The remarkable mechanical strength of SasG arises from tandemly arrayed 'clamp' motifs within the folded domains. Our findings reveal an elegant minimal solution for the assembly of monomeric mechano-resistant tethers of variable length.

Contact author

• Fiona Whelan

Models

• Model #235: ; Type: atomic / Software: SASREF / Radius of dummy atoms: 1.90 A / Chi-square value: 1.1236; Search similar-shape structures of this assembly by Omokage search (details)
• Model #236: ; Type: dummy / Software: Gasbor / Radius of dummy atoms: 1.90 A / Chi-square value: 1.1236; Search similar-shape structures of this assembly by Omokage search (details)

Sample

• Sample: Name: Surface Protein G (SasG) EG5 repeat protein G51-G52 / Specimen concentration: 7.5 mg/ml
• Buffer: Name: Tris / Concentration: 20.00 mM / pH: 7.5 / Composition: 200 mM NaCl, 1 mM EDTA, 20 mM Tris.Cl

Entity #140

Name: SasG / Type: protein / Description: Surface protein G / Formula weight: 23.729 / Num. of mol.: 1 / Source: Staphylococcus aureus / References: UniProt: Q2G2B2
Sequence:

GPHMAPKTIT ELEKKVEEIP FKKERKFNPD LAPGTEKVTR EGQKGEKTIT TPTLKNPLTG VIISKGEPKE EITKDPINEL TEYGPETIAP GHRDEFDPKL PTGEKEEVPG KPGIKNPETG DVVRPPVDSV TKYGPVKGDS IVEKEEIPFE KERKFNPDLA PGTEKVTREG QKGEKTITTP TLKNPLTGEI ISKGESKEEI TKDPINELTE YGPET

Experimental information

• Beam: Instrument name: PETRA III P12 / City: Hamburg / 国: Germany / Type of source: X-ray synchrotronSynchrotron / Wavelength: 0.12 Å / Dist. spec. to detc.: 3.1 mm
• Detector: Name: Pilatus 2M

Scan

Title: G51-G52 / Measurement date: Nov 12, 2013 / Cell temperature: 10 °C / Exposure time: 0.05 sec. / Number of frames: 20 / Unit: 1/nm /

	Min	Max
Q	0.0686	4.4884

Distance distribution function P(R)

Sofotware P(R): GNOM 4.6 / Number of points: 420 /

	Min	Max
Q	0.006989	0.4484
P(R) point	15	434
R	0	190

Result

D max: 19 / Type of curve: single_conc
Comments: SAXS was used to determine whether the EG5 repeat forms an extended rod-like structure in solution.

	Experimental	Standard	Porod
MW	20.3 kDa	20.3 kDa	23.7 kDa
Volume	-	-	28.6 nm3

	P(R)	Guinier
Forward scattering, I0	4206	4140.4
Radius of gyration, Rg	5.08 nm	4.72 nm