New insights into transcriptional regulation by H-NS.
H-NS, a nucleoid-associated DNA-binding protein of enteric bacteria, was discovered 35 years ago and subsequently found to exert widespread and highly pleiotropic effects on gene regulation. H-NS binds to high-affinity sites and spreads along adjacent AT-rich DNA to silence transcription. Preferential binding to sequences with higher AT-content than the resident genome allows H-NS to repress the expression of foreign DNA in a process known as 'xenogeneic silencing.' Counter-silencing by a variety of mechanisms facilitates the evolutionary acquisition of horizontally transferred genes and their integration into pre-existing regulatory networks. This review will highlight recent insights into the mechanism and biological importance of H-NS-DNA interactions.
Fang
Ferric C
FC
Department of Laboratory Medicine, University of Washington School of Medicine, 1959 NE Pacific Street, Box 357242, Seattle, WA 98195-7242 USA. fcfang@u.washington.edu
Rimsky
Sylvie
S
D000595:Amino Acid Sequence; D001419:Bacteria / Q000235:genetics / Q000378:metabolism*; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D001483:Base Sequence; D004268:DNA-Binding Proteins / Q000378:metabolism*; D015964:Gene Expression Regulation, Bacterial; D008969:Molecular Sequence Data; D014158:Transcription, Genetic
D001426:Bacterial Proteins; D004268:DNA-Binding Proteins; C031908:H-NS protein, bacteria