Download MendeleyThe MotA transcription factor from bacteriophage T4 contains a novel DNA-binding domain: the 'double wing' motif.
Li, N., Sickmier, E.A., Zhang, R., Joachimiak, A., White, S.W.(2002) Mol Microbiol 43: 1079-1088
- PubMed: 11918797
- DOI: https://doi.org/10.1046/j.1365-2958.2002.02809.x
- Primary Citation of Related Structures:
1KAF - PubMed Abstract:
MotA is a transcription factor from bacteriophage T4 that helps adapt the host Escherichia coli transcription apparatus to T4 middle promoters. We have determined the crystal structure of the C-terminal DNA-binding domain of MotA (MotCF) to 1.6 A resolution using multiwavelength, anomalous diffraction methods. The structure reveals a novel DNA-binding alpha/beta motif that contains an exposed beta-sheet surface that mediates interactions with the DNA. Independent biochemical experiments have shown that MotCF binds to one surface of a single turn of DNA through interactions in adjacent major and minor grooves. We present a model of the interaction in which beta-ribbons at opposite corners of the six-stranded beta-sheet penetrate the DNA grooves, and call the motif a 'double wing' to emphasize similarities to the 'winged-helix' motif. The model is consistent with data on how MotA functions at middle promoters, and provides an explanation for why MotA can form non-specific multimers on DNA.
Organizational Affiliation:
Department of Structural Biology, St Jude Children's Research Hospital, Memphis, TN 38105, USA.
