1rr7
From Proteopedia
(New page: 200px<br /><applet load="1rr7" size="450" color="white" frame="true" align="right" spinBox="true" caption="1rr7, resolution 2.2Å" /> '''Crystal structure of ...) |
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| - | [[Image:1rr7.gif|left|200px]]<br /><applet load="1rr7" size=" | + | [[Image:1rr7.gif|left|200px]]<br /><applet load="1rr7" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1rr7, resolution 2.2Å" /> | caption="1rr7, resolution 2.2Å" /> | ||
'''Crystal structure of the Middle Operon Regulator protein of Bacteriophage Mu'''<br /> | '''Crystal structure of the Middle Operon Regulator protein of Bacteriophage Mu'''<br /> | ||
==Overview== | ==Overview== | ||
| - | Transcription from the middle promoter, Pm, of bacteriophage Mu requires | + | Transcription from the middle promoter, Pm, of bacteriophage Mu requires the phage-encoded activator protein Mor and bacterial RNA polymerase. Mor is a sequence-specific DNA-binding protein that mediates transcription activation through its interactions with the C-terminal domains of the alpha and sigma subunits of bacterial RNA polymerase. Here we present the first structure for a member of the Mor/C family of transcription activators, the crystal structure of Mor to 2.2-A resolution. Each monomer of the Mor dimer is composed of two domains, the N-terminal dimerization domain and C-terminal DNA-binding domain, which are connected by a linker containing a beta strand. The N-terminal dimerization domain has an unusual mode of dimerization; helices alpha1 and alpha2 of both monomers are intertwined to form a four-helix bundle, generating a hydrophobic core that is further stabilized by antiparallel interactions between the two beta strands. Mutational analysis of key leucine residues in helix alpha1 demonstrated a role for this hydrophobic core in protein solubility and function. The C-terminal domain has a classical helix-turn-helix DNA-binding motif that is located at opposite ends of the elongated dimer. Since the distance between the two helix-turn-helix motifs is too great to allow binding to two adjacent major grooves of the 16-bp Mor-binding site, we propose that conformational changes in the protein and DNA will be required for Mor to interact with the DNA. The highly conserved glycines flanking the beta strand may act as pivot points, facilitating the conformational changes of Mor, and the DNA may be bent. |
==About this Structure== | ==About this Structure== | ||
| - | 1RR7 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Enterobacteria_phage_mu Enterobacteria phage mu] with PT as [http://en.wikipedia.org/wiki/ligand ligand]. Full crystallographic information is available from [http:// | + | 1RR7 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Enterobacteria_phage_mu Enterobacteria phage mu] with <scene name='pdbligand=PT:'>PT</scene> as [http://en.wikipedia.org/wiki/ligand ligand]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1RR7 OCA]. |
==Reference== | ==Reference== | ||
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[[Category: Enterobacteria phage mu]] | [[Category: Enterobacteria phage mu]] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
| - | [[Category: Howe, M | + | [[Category: Howe, M M.]] |
[[Category: Kumaraswami, M.]] | [[Category: Kumaraswami, M.]] | ||
| - | [[Category: Park, H | + | [[Category: Park, H W.]] |
[[Category: PT]] | [[Category: PT]] | ||
[[Category: mor]] | [[Category: mor]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 14:53:52 2008'' |
Revision as of 12:53, 21 February 2008
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Crystal structure of the Middle Operon Regulator protein of Bacteriophage Mu
Overview
Transcription from the middle promoter, Pm, of bacteriophage Mu requires the phage-encoded activator protein Mor and bacterial RNA polymerase. Mor is a sequence-specific DNA-binding protein that mediates transcription activation through its interactions with the C-terminal domains of the alpha and sigma subunits of bacterial RNA polymerase. Here we present the first structure for a member of the Mor/C family of transcription activators, the crystal structure of Mor to 2.2-A resolution. Each monomer of the Mor dimer is composed of two domains, the N-terminal dimerization domain and C-terminal DNA-binding domain, which are connected by a linker containing a beta strand. The N-terminal dimerization domain has an unusual mode of dimerization; helices alpha1 and alpha2 of both monomers are intertwined to form a four-helix bundle, generating a hydrophobic core that is further stabilized by antiparallel interactions between the two beta strands. Mutational analysis of key leucine residues in helix alpha1 demonstrated a role for this hydrophobic core in protein solubility and function. The C-terminal domain has a classical helix-turn-helix DNA-binding motif that is located at opposite ends of the elongated dimer. Since the distance between the two helix-turn-helix motifs is too great to allow binding to two adjacent major grooves of the 16-bp Mor-binding site, we propose that conformational changes in the protein and DNA will be required for Mor to interact with the DNA. The highly conserved glycines flanking the beta strand may act as pivot points, facilitating the conformational changes of Mor, and the DNA may be bent.
About this Structure
1RR7 is a Single protein structure of sequence from Enterobacteria phage mu with as ligand. Full crystallographic information is available from OCA.
Reference
Crystal structure of the Mor protein of bacteriophage Mu, a member of the Mor/C family of transcription activators., Kumaraswami M, Howe MM, Park HW, J Biol Chem. 2004 Apr 16;279(16):16581-90. Epub 2004 Jan 16. PMID:14729670
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