Cloning, expression, purification, crystallization and preliminary X-ray diffraction analysis of an ASCH domain-containing protein from Zymomonas mobilis ZM4

The human activating signal cointegrator 1 (ASC-1) homology (ASCH) domain is frequently observed in many organisms, although its function has not yet been clearly defined. In Zymomonas mobilis ZM4, the ZMO0922 gene encodes a polypeptide that includes an ASCH domain (zmASCH). To provide a better structural background for the probable role of ASCH domain-containing proteins, the ZMO0922 gene was cloned and expressed. The purified protein was crystallized from 30%(w/v) polyethylene glycol 400, 0.1 M cacodylic acid pH 6.5 and 0.2 M lithium sulfate. Diffraction data were collected to 2.1 Å resolution using synchrotron radiation. The crystal belonged to the primitive trigonal space group P3₁21 or P3₂21, with unit-cell parameters a = b = 51.67, c = 207.30 Å, α = β = 90, γ = 120°. Assuming the presence of one molecule in the asymmetric unit gave a Matthews coefficient of 4.69 ų Da⁻¹, corresponding to a solvent content of 73.7%.