Purification and N-terminal amino acid sequences of Chlamydia trachomatis histone analogs.

DNA-binding proteins specific to Chlamydia trachomatis elementary bodies have been described and recently characterized as procaryotic histone analogs. I have developed an affinity purification procedure for the 18-kDa histone analog, Hc1, based on its affinity for polyanions. The availability of highly purified Hc1 has allowed for determination of its N-terminal amino acid sequence and should prove useful in studies of its biological function. The variable C. trachomatis histone analog not obtained by this procedure was electrophoresed onto Immobilon paper for sequencing. The N terminus of the variable histone was conserved among C. trachomatis serotypes L2, D, and B and was distinct from that of Hc1.