Crystal Structure of a Complex of DNA with One AT-Hook of HMGA1

We present here for the first time the crystal structure of an AT-hook domain. We show the structure of an AT-hook of the ubiquitous nuclear protein HMGA1, combined with the oligonucleotide d(CGAATTAATTCG)2, which has two potential AATT interacting groups. Interaction with only one of them is found. The structure presents analogies and significant differences with previous NMR studies: the AT-hook forms hydrogen bonds between main-chain NH groups and thymines in the minor groove, DNA is bent and the minor groove is widened

Crystal structure of a yeast TFIIA/TBP/DNA complex

The X-ray crystal structure of the transcription factor IIA (TFIIA)in complex with the TATA-box-binding protein (TBP) and TATA-element DNA is presented at 2.5 Å resolution. TFIIA is composed of a β-barrel and a four-helix bundle motif that together have a boot-like appearance. The β-barrel extends the TBP β-sheet and bridges over the DNA major groove immediately upstream of the TATA box. The four-helix bundle contributes substantially to the surface of the complex available for interaction with additional transcription factors