1qx8
From Proteopedia
(New page: 200px<br /><applet load="1qx8" size="450" color="white" frame="true" align="right" spinBox="true" caption="1qx8, resolution 2.02Å" /> '''Crystal structure of...) |
|||
| Line 1: | Line 1: | ||
| - | [[Image:1qx8.gif|left|200px]]<br /><applet load="1qx8" size=" | + | [[Image:1qx8.gif|left|200px]]<br /><applet load="1qx8" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1qx8, resolution 2.02Å" /> | caption="1qx8, resolution 2.02Å" /> | ||
'''Crystal structure of a five-residue deletion mutant of the Rop protein'''<br /> | '''Crystal structure of a five-residue deletion mutant of the Rop protein'''<br /> | ||
==Overview== | ==Overview== | ||
| - | The repressor of primer (Rop) protein has become a steady source of | + | The repressor of primer (Rop) protein has become a steady source of surprises concerning the relationship between the sequences and the structures of several of its mutants and variants. Here we add another piece to the puzzle of Rop by showing that an engineered deletion mutant of the protein (corresponding to a deletion of residues 30-34 of the wild-type protein and designed to restore the heptad periodicity at the turn region) results in a complete reorganization of the bundle which is converted from a homodimer to a homotetramer. In contrast (and as previously shown), a two-residue insertion, which also restores the heptad periodicity, is essentially identical with wild-type Rop. The new deletion mutant structure is a canonical, left-handed, all-antiparallel bundle with a completely different hydrophobic core and distinct surface properties. The structure agrees and qualitatively explains the results from functional, thermodynamic, and kinetic studies which indicated that this deletion mutant is a biologically inactive hyperstable homotetramer. Additional insight into the stability and dynamics of the mutant structure has been obtained from extensive molecular dynamics simulations in explicit water and with full treatment of electrostatics. |
==About this Structure== | ==About this Structure== | ||
| - | 1QX8 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli]. Full crystallographic information is available from [http:// | + | 1QX8 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1QX8 OCA]. |
==Reference== | ==Reference== | ||
| Line 14: | Line 14: | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
[[Category: Cesareni, G.]] | [[Category: Cesareni, G.]] | ||
| - | [[Category: Glykos, N | + | [[Category: Glykos, N M.]] |
[[Category: Kokkinidis, M.]] | [[Category: Kokkinidis, M.]] | ||
[[Category: Kotsifaki, D.]] | [[Category: Kotsifaki, D.]] | ||
| Line 21: | Line 21: | ||
[[Category: replication; initiation of transcription; rna primer; x-ray]] | [[Category: replication; initiation of transcription; rna primer; x-ray]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 14:44:40 2008'' |
Revision as of 12:44, 21 February 2008
|
Crystal structure of a five-residue deletion mutant of the Rop protein
Overview
The repressor of primer (Rop) protein has become a steady source of surprises concerning the relationship between the sequences and the structures of several of its mutants and variants. Here we add another piece to the puzzle of Rop by showing that an engineered deletion mutant of the protein (corresponding to a deletion of residues 30-34 of the wild-type protein and designed to restore the heptad periodicity at the turn region) results in a complete reorganization of the bundle which is converted from a homodimer to a homotetramer. In contrast (and as previously shown), a two-residue insertion, which also restores the heptad periodicity, is essentially identical with wild-type Rop. The new deletion mutant structure is a canonical, left-handed, all-antiparallel bundle with a completely different hydrophobic core and distinct surface properties. The structure agrees and qualitatively explains the results from functional, thermodynamic, and kinetic studies which indicated that this deletion mutant is a biologically inactive hyperstable homotetramer. Additional insight into the stability and dynamics of the mutant structure has been obtained from extensive molecular dynamics simulations in explicit water and with full treatment of electrostatics.
About this Structure
1QX8 is a Single protein structure of sequence from Escherichia coli. Full crystallographic information is available from OCA.
Reference
Loopless Rop: structure and dynamics of an engineered homotetrameric variant of the repressor of primer protein., Glykos NM, Papanikolau Y, Vlassi M, Kotsifaki D, Cesareni G, Kokkinidis M, Biochemistry. 2006 Sep 12;45(36):10905-19. PMID:16953576
Page seeded by OCA on Thu Feb 21 14:44:40 2008
