4BHU

Crystal structure of BslA - A bacterial hydrophobin

Summary for 4BHU

• Entry DOI: 10.2210/pdb4bhu/pdb
• Descriptor: UNCHARACTERIZED PROTEIN YUAB, GLYCEROL, CHLORIDE ION, ... (5 entities in total)
• Functional Keywords: structural protein, biofilm
• Biological source: BACILLUS SUBTILIS SUBSP. SUBTILIS; More
• Cellular location: Membrane; Single-pass membrane protein (Potential): P71014 P71014
• Total number of polymer chains: 10
• Total formula weight: 142035.37

Authors

Rao, F.V.,Hobley, L.,Ostrowski, A.,Bromley, K.M.,Porter, M.,Prescott, A.R.,Swedlow, J.R.,MacPhee, C.E.,van Aalten, D.M.F.,Stanley-Wall, N.R. (deposition date: 2013-04-08, release date: 2013-08-14, Last modification date: 2013-08-28)

Primary citation

Hobley, L.,Ostrowski, A.,Rao, F.V.,Bromley, K.M.,Porter, M.,Prescott, A.R.,Macphee, C.E.,Van Aalten, D.M.F.,Stanley-Wall, N.R.
Bsla is a Self-Assembling Bacterial Hydrophobin that Coats the Bacillus Subtilis Biofilm.
Proc.Natl.Acad.Sci.USA, 110:13600-, 2013

PubMed Abstract: Biofilms represent the predominant mode of microbial growth in the natural environment. Bacillus subtilis is a ubiquitous Gram-positive soil bacterium that functions as an effective plant growth-promoting agent. The biofilm matrix is composed of an exopolysaccharide and an amyloid fiber-forming protein, TasA, and assembles with the aid of a small secreted protein, BslA. Here we show that natively synthesized and secreted BslA forms surface layers around the biofilm. Biophysical analysis demonstrates that BslA can self-assemble at interfaces, forming an elastic film. Molecular function is revealed from analysis of the crystal structure of BslA, which consists of an Ig-type fold with the addition of an unusual, extremely hydrophobic "cap" region. A combination of in vivo biofilm formation and in vitro biophysical analysis demonstrates that the central hydrophobic residues of the cap are essential to allow a hydrophobic, nonwetting biofilm to form as they control the surface activity of the BslA protein. The hydrophobic cap exhibits physiochemical properties remarkably similar to the hydrophobic surface found in fungal hydrophobins; thus, BslA is a structurally defined bacterial hydrophobin. We suggest that biofilms formed by other species of bacteria may have evolved similar mechanisms to provide protection to the resident bacterial community.

PubMed: 23904481
DOI: 10.1073/PNAS.1306390110

Experimental method

X-RAY DIFFRACTION (1.91 Å)