Substrate specificity of Helicobacter pylori histone-like HU protein is determined by insufficient stabilization of DNA flexure points.

ABSTRACT: The histone-like HU protein is ubiquitous in the eubacteria. A role for Escherichia coli HU in compaction of the bacterial genome has been reported, along with regulatory roles in DNA replication, transposition, repair and transcription. We show here that HU from the human pathogen Helicobacter pylori, which has been implicated in the development of ulcers and gastric cancer, exhibits enhanced thermal stability and distinct DNA substrate specificity. Thermal denaturation of HpyHU (H. pylori HU) measured by CD spectroscopy yields a melting temperature (T(m)) of 56.4+/-0.1 degrees C. HpyHU binds linear duplex DNA with a site size of approximately 19 bp and with low affinity, but in striking contrast to E. coli HU, HpyHU has only modest preference for DNA with mismatches, nicks or gaps. Inste

SUBMITTER: Chen C 

PROVIDER: S-EPMC1134076 | biostudies-literature | 2004 Oct

REPOSITORIES: biostudies-literature