Protein preparation, crystallization and preliminary X-ray analysis of human adrenal gland protein AD-004.

The adrenal gland protein AD-004 was identified in the human adrenal gland. Full-length AD-004 contains 172 amino acids, with a predicted molecular weight of about 20 kDa. In attempts to crystallize human AD-004, the gene was subcloned into a modified pET vector, pET21-DEST, with an N-terminal His5 tag using the Gateway cloning system, followed by protein expression in Escherichia coli strain BL21(DE3). The protein was purified in two steps to near-homogeneity and was crystallized. The crystals belong to space group P6₁ or P6₅, with unit-cell parameters a = b = 99.56, c = 57.19 Å. A complete 2.0 Å data set has been collected at a rotating-anode X-ray source and structure determination is under way. [ABSTRACT FROM AUTHOR]