Heterologous Expression of the Alba Protein from the Hyperthermophilic Archaeon Aeropyrum Pernix

Nucleic acid binding proteins have important roles in DNA and RNA packaging, stabilisation and repair, and in gene regulation, and they are therefore essential for all organisms. All of the known hyperthermophiles have at least one DNA sequence encoding for the Alba proteins. The Alba proteins are small (approximately 10 kDa), DNA-binding, basic proteins that appear to partly compensate for the lack of histones in the archaea Aeropyrum pernix and other hyperthermophiles. Two sequences of these potential histone counterparts, the Alba proteins, were identified in the Aeropyrum pernix genome (APE1832.1 and APE1823). By using a wide range of experimental techniques and by examining several combinations of expression systems the expression of recombinant Alba1 and Alba2 proteins was optimized. Co-expression of both of the Alba proteins was needed when isolating recombinant Alba2. The purification of both recombinant Alba1 and Alba2 His-tagged proteins were simplyfied in satisfactory yield. The electrophoretic mobility shift assay demonstrated the ability of the Alba1 and Alba2 proteins from Aeropyrum pernix to bind DNA. (doi: 10.5562/cca1772)