Journal:Acta Cryst D:S205979832100632X
From Proteopedia
(Difference between revisions)
| Line 4: | Line 4: | ||
<hr/> | <hr/> | ||
<b>Molecular Tour</b><br> | <b>Molecular Tour</b><br> | ||
| - | Homeodomain (HD) containing transcription factors are one of the most important regulators of morphology and differentiation in fungi, animals and plants. Among different types of HD containing transcriptional regulators, the WUCHEL-RELATED HOMEOBOX (WOX) family is unique to plants and instructs plant growth and development. The Medicago truncatula STENOFOLIA (STF) is a master regulator of leaf blade lateral development. Here, we report the crystal structure of the HD of STF in complex with its promoter DNA at 2.1 Å resolution. <scene name='88/886037/Cv/4'>STF-HD dimer</scene> (HDA in green, HDB in yellow) bound on a 22-bps DNA (color in magenta and alice blue for each strand respectively) in the ASU. <scene name='88/886037/Cv/8'>STF-HD binds DNA as a unique unprecedented tetramer</scene>, enclosing nearly entire bound DNA surface. Depicted are four STF-HDs (HDA' in blue and HDB' in wheat) bound on the DNA. HDA/HDA' and HDB/HDB' are crystallographic symmetry mates, respectively. A second DNA molecule in crystal packing is shown (DNAsym, colored in light pink and teal) forming a pseudo-continuous helix. <scene name='88/886037/Cv/13'>The electropotential of STF-HD tetramer</scene> is shown in sacefill representaion. The bound dsDNA is shown as cartoons. Notice nearly the entire DNA surface is clamped by the protein. Although the target promoter DNA sequence contains a mixture of 'TGA' and 'TAAT' motifs, STF-HD specifically binds 'TGA'. Major groove DNA base recognitions: | + | Homeodomain (HD) containing transcription factors are one of the most important regulators of morphology and differentiation in fungi, animals and plants. Among different types of HD containing transcriptional regulators, the WUCHEL-RELATED HOMEOBOX (WOX) family is unique to plants and instructs plant growth and development. The Medicago truncatula STENOFOLIA (STF) is a master regulator of leaf blade lateral development. Here, we report the crystal structure of the HD of STF in complex with its promoter DNA at 2.1 Å resolution. <scene name='88/886037/Cv/4'>STF-HD dimer</scene> (HDA in green, HDB in yellow) bound on a 22-bps DNA (color in magenta and alice blue for each strand respectively) in the ASU. <scene name='88/886037/Cv/8'>STF-HD binds DNA as a unique unprecedented tetramer</scene>, enclosing nearly entire bound DNA surface. Depicted are four STF-HDs (HDA' in blue and HDB' in wheat) bound on the DNA. HDA/HDA' and HDB/HDB' are crystallographic symmetry mates, respectively. A second DNA molecule in crystal packing is shown (DNAsym, colored in light pink and teal) forming a pseudo-continuous helix. <scene name='88/886037/Cv/13'>The electropotential of STF-HD tetramer</scene> is shown in sacefill representaion. The bound dsDNA is shown as cartoons. Notice nearly the entire DNA surface is clamped by the protein. Although the target promoter DNA sequence contains a mixture of 'TGA' and 'TAAT' motifs, STF-HD specifically binds 'TGA'. |
| + | |||
| + | Major groove DNA base recognitions: | ||
| + | *<scene name='88/886037/Cv/28'>'TGA'</scene> (in cyan). | ||
*<scene name='88/886037/Cv/27'>'TGA' recognition by STF-HDA helix alpha3</scene> (green). | *<scene name='88/886037/Cv/27'>'TGA' recognition by STF-HDA helix alpha3</scene> (green). | ||
| + | |||
When compared to DNA recognition by other HDs, the 'base reader' helix alpha 3 in STF-HD not only specifies DNA sequence in the major groove of DNA, but also interacts with DNA from the minor groove providing important interactions. Our structure based mutagenesis and functional studies in planta support the structural observations. The findings from this study provide new insights into the DNA binding mechanisms of plant specific HDs from WOX family or transcription factors. | When compared to DNA recognition by other HDs, the 'base reader' helix alpha 3 in STF-HD not only specifies DNA sequence in the major groove of DNA, but also interacts with DNA from the minor groove providing important interactions. Our structure based mutagenesis and functional studies in planta support the structural observations. The findings from this study provide new insights into the DNA binding mechanisms of plant specific HDs from WOX family or transcription factors. | ||
Revision as of 15:46, 22 June 2021
| |||||||||||
This page complements a publication in scientific journals and is one of the Proteopedia's Interactive 3D Complement pages. For aditional details please see I3DC.
