Cloning and expression of the hup encoding a histone-like protein of Campylobacter jejuni.

A Campylobacter jejuni gene, designated hup, that appears to encode a homolog of the histone-like DNA-binding protein, HU, has been cloned, sequenced and expressed in Escherichia coli. Immunoblotting and in vitro transcription/translation analyses revealed a 11-kDa protein that was produced by recombinant plasmids containing hup. The gene contains an open reading frame (ORF) sufficient to encode a protein of 98 amino acids (aa) with a calculated molecular mass of 10,267 Da and a predicted isoelectric point of 10.1. The deduced aa sequence of the protein, designated HCj, exhibits considerable sequence identity with members of the HU family of proteins from other eubacterial species. The transcription start point was identified by primer extension analysis and appropriately spaced promoter sequences were found which exhibit considerable similarity to E. coli and Bacillus promoters. Southern hybridization analyses indicate that C. jejuni has a single copy of hup.