NUCLEAR MAGNETIC RESONANCE-BASED MODEL OF A TF1 HMU-DNA COMPLEX/

Transcription factor 1 (TF1), a type II DNA-binding protein encoded by the Bacillus subtilis bacteriophage SPO1, has the capacity for sequen ce-selective DNA binding and a preference for 5-hydroxymethyl-2'-deoxy uridine (HmU)-containing DNA. In NMR studies of the TF1/HmU-DNA comple x, intermolecular NOEs indicate that the flexible beta-ribbon and C-te rminal alpha-helix are involved in the DNA-binding site of TF1, placin g it in the beta-sheet category of DNA-binding proteins proposed to bi nd by wrapping two beta-ribbon ''arms'' around the DNA. Intermolecular and intramolecular NOEs were used to generate an energy-minimized mod el of the protein-DNA complex in which both DNA bending and protein st ructure changes are evident. (C) 1997 Academic Press.