Refolding, crystallization and preliminary X-ray crystallographic studies of the ?-barrel domain of BamA, a membrane protein essential for outer membrane protein biogenesis.

ABSTRACT: In Gram-negative bacteria, the assembly of outer membrane proteins (OMPs) requires a five-protein ?-barrel assembly machinery (BAM) complex, of which BamA is an essential and evolutionarily conserved integral outer membrane protein. Here, the refolding, crystallization and preliminary X-ray crystallographic characterization of the ?-barrel domain of BamA from Escherichia coli (EcBamA) are reported. Native and selenomethionine-substituted EcBamA proteins were crystallized at 16°C and X-ray diffraction data were collected to 2.6 and 3.7?Å resolution, respectively. The native crystals belonged to space group P21212, with unit-cell parameters a = 118.492, b = 159.883, c = 56.000?Å and two molecules in one asymmetric unit; selenomethionine-substituted protein crystals belonged to space group P4322, with unit-cell parameters a = b = 163.162, c = 46.388?Å and one molecule in one asymmetric unit. Initial phases for EcBamA ?-barrel domain were obtained from a SeMet SAD data set. These preliminary X-ray crystallographic studies paved the way for further structural determination of the ?-barrel domain of EcBamA.

SUBMITTER: Ni D 

PROVIDER: S-EPMC3944703 | biostudies-literature | 2014 Mar

REPOSITORIES: biostudies-literature