Open AccessCloning, expression, purification, crystallization and preliminary crystallographic analysis of the N‐terminal domain of serine glutamate repeat A (SgrA) protein from Enterococcus faecium
Author(s) -
Nagarajan Revathi,
Hendrickx Antoni P. A.,
Ponnuraj Karthe
Publication year - 2013
Publication title -
acta crystallographica section f
Language(s) - English
Resource type - Journals
ISSN - 1744-3091
DOI - 10.1107/s1744309113005745
Subject(s) - biology , bacterial adhesin , enterococcus faecium , ligand (biochemistry) , escherichia coli , microbiology and biotechnology , extracellular , biochemistry , bacteria , receptor , genetics , gene
Serine glutamate repeat A (SgrA) protein is an LP x TG surface adhesin of Enterococcus faecium and is the first bacterial nidogen‐binding protein identified to date. It has been suggested that it binds to human nidogen, the extracellular matrix molecule of basal lamina, and plays a key role in the invasion and colonization of eukaryotic host cells. SgrA 28–288 , having both a putative ligand‐binding A domain and repetitive B domain, was expressed in Escherichia coli and purified using Ni‐affinity and hydrophobic interaction chromatography. Further, the putative ligand‐binding region, rSgrA 28–153 , was subcloned, overexpressed and purified in both native and selenomethionine‐derivative forms. The native rSgrA 28–153 protein crystallized in the monoclinic space group P 2 1 and diffracted to 3.3 Å resolution using an in‐house X‐ray source, with unit‐cell parameters a = 35.84, b = 56.35, c = 60.20 Å, β = 106.5°.