TY  - JOUR
AU  - Baranova, E.
AU  - Fronzes, R.
AU  - Garcia-Pino, A.
AU  - Van Gerven, N.
AU  - Papapostolou, D.
AU  - Pehau-Arnaudet, G.
AU  - Pardon, E.
AU  - Steyaert, J.
AU  - Howorka, S.
AU  - Remaut, H.
AU  - DESY
TI  - SbsB structure and lattice reconstruction unveil Ca<sup>2<sup>+</sup></sup> triggered S-layer assembly
JO  - Nature 
VL  - 487
SN  - 0028-0836
CY  - London [u.a.]
PB  - Nature Publ. Group
M1  - PHPPUBDB-25515
SP  - 119 - 122
PY  - 2012
AB  - S-layers are regular two-dimensional semipermeable protein layers that constitute a major cell-wall component in archaea and many bacteria. The nanoscale repeat structure of the S-layer lattices and their self-assembly from S-layer proteins (SLPs) have sparked interest in their use as patterning and display scaffolds for a range of nano-biotechnological applications. Despite their biological abundance and the technological interest in them, structural information about SLPs is limited to truncated and assembly-negative proteins. Here we report the X-ray structure of the SbsB SLP of Geobacillus stearothermophilus PV72/p2 by the use of nanobody-aided crystallization. SbsB consists of a seven-domain protein, formed by an amino-terminal cell-wall attachment domain and six consecutive immunoglobulin-like domains, that organize into a φ-shaped disk-like monomeric crystallization unit stabilized by interdomain Ca(2+) ion coordination. A Ca(2+)-dependent switch to the condensed SbsB quaternary structure pre-positions intermolecular contact zones and renders the protein competent for S-layer assembly. On the basis of crystal packing, chemical crosslinking data and cryo-electron microscopy projections, we present a model for the molecular organization of this SLP into a porous protein sheet inside the S-layer. The SbsB lattice represents a previously undescribed structural model for protein assemblies and may advance our understanding of SLP physiology and self-assembly, as well as the rational design of engineered higher-order structures for biotechnology.
KW  - Bacterial Proteins: chemistry
KW  - Bacterial Proteins: metabolism
KW  - Calcium: chemistry
KW  - Calcium: metabolism
KW  - Calcium: pharmacology
KW  - Cryoelectron Microscopy
KW  - Crystallization: methods
KW  - Crystallography, X-Ray
KW  - Geobacillus stearothermophilus: chemistry
KW  - Immunoglobulins: chemistry
KW  - Membrane Proteins: chemistry
KW  - Membrane Proteins: metabolism
KW  - Models, Molecular
KW  - Molecular Dynamics Simulation
KW  - Nanostructures: chemistry
KW  - Polymerization: drug effects
KW  - Protein Structure, Quaternary: drug effects
KW  - Protein Structure, Tertiary: drug effects
KW  - Solutions
KW  - Bacterial Proteins (NLM Chemicals)
KW  - Immunoglobulins (NLM Chemicals)
KW  - Membrane Proteins (NLM Chemicals)
KW  - SbsB protein, Bacillus stearothermophilus (NLM Chemicals)
KW  - Solutions (NLM Chemicals)
KW  - Calcium (NLM Chemicals)
LB  - PUB:(DE-HGF)16
C6  - pmid:22722836
UR  - <Go to ISI:>//WOS:000305982900062
DO  - DOI:10.1038/nature11155
UR  - https://bib-pubdb1.desy.de/record/142539
ER  -