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