Structural and functional insights into peptidoglycan access for the lytic amidase LytA of Streptococcus pneumoniae.

Mellroth P, Sandalova T, Kikhney A, Vilaplana F, Hesek D, Lee M, Mobashery S, Normark S, Svergun D, Henriques-Normark B, Achour A, MBio 5(1):e01120-13 (2014) Europe PMC

SASDBJ4 – Wild-type LytA choline-binding domain

Lytic Amidase choline-binding domain
MWI(0) 31 kDa
MWexpected 17 kDa
VPorod 49 nm3
log I(s) 2.98×101 2.98×100 2.98×10-1 2.98×10-2
Lytic Amidase choline-binding domain small angle scattering data  s, nm-1
ln I(s)
Lytic Amidase choline-binding domain Guinier plot ln 2.98×101 Rg: 3.3 nm 0 (3.3 nm)-2 s2
(sRg)2I(s)/I(0)
Lytic Amidase choline-binding domain Kratky plot 1.104 0 √3 sRg
p(r)
Lytic Amidase choline-binding domain pair distance distribution function Rg: 3.1 nm 0 Dmax: 10 nm

Data validation

Fits and models

log I(s)
 s, nm-1
Lytic Amidase choline-binding domain SASREF model
Synchrotron SAXS data from solutions of Wild-type LytA choline-binding domain in 20 mM Tris 150 mM NaCl 5 mM choline chloride 1 µM ZnCl2, pH 7.5 were collected on the EMBL X33 beam line at the DORIS III, DESY storage ring (Hamburg, Germany) using a Pilatus 1M-W detector at a sample-detector distance of 2.7 m and at a wavelength of λ = 0.15 nm (I(s) vs s, where s = 4πsinθ/λ, and 2θ is the scattering angle). Solute concentrations ranging between 0.7 and 6.9 mg/ml were measured at 10°C. Eight successive 15 second frames were collected. The data were normalized to the intensity of the transmitted beam and radially averaged; the scattering of the solvent-blank was subtracted.

The CBD of wt-LytA forms a dimer in solution, in line with results from the crystal structure.

Tags: X33
Lytic Amidase choline-binding domain (LytA CBD)
Mol. type   Protein
Organism   Streptococcus pneumoniae
Olig. state   Dimer
Mon. MW   17.3 kDa