1KAF

DNA Binding Domain Of The Phage T4 Transcription Factor MotA (AA105-211)

Summary for 1KAF

• Entry DOI: 10.2210/pdb1kaf/pdb
• Related: 1BJA 1I1s
• Descriptor: Transcription regulatory protein MOTA (2 entities in total)
• Functional Keywords: escherichia coli; x-ray crystallography; protein-dna interactions; structural genomics; eubacterial promoters., transcription
• Biological source: Enterobacteria phage T4
• Total number of polymer chains: 6
• Total formula weight: 75231.35

Authors

Li, N.,Sickmier, E.A.,Zhang, R.,Joachimiak, A.,White, S.W. (deposition date: 2001-11-01, release date: 2001-11-21, Last modification date: 2024-05-22)

Primary citation

Li, N.,Sickmier, E.A.,Zhang, R.,Joachimiak, A.,White, S.W.
The MotA transcription factor from bacteriophage T4 contains a novel DNA-binding domain: the 'double wing' motif.
Mol.Microbiol., 43:1079-1088, 2002

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.

PubMed: 11918797
DOI: 10.1046/j.1365-2958.2002.02809.x

Experimental method

X-RAY DIFFRACTION (1.6 Å)