2qpe: Difference between revisions

Revision as of 19:41, 21 February 2008

An unexpected outcome of surface-engineering an integral membrane protein: Improved crystallization of cytochrome ba3 oxidase from Thermus thermophilus

OverviewOverview

Cytochrome ba(3) oxidase is an integral membrane protein identified in the thermophilic bacterium Thermus thermophilus. The enzyme has now been expressed recombinantly and purified with a histidine tag. As such, it crystallizes under similar conditions and in the same space group (P4(3)2(1)2) as the native protein. A novel cryoprotection scheme is described here to obtain high-resolution diffraction from these crystals, which involves soaking in a mixture of glycerol and ethylene glycol under a layer of oil. The unit-cell parameters for these crystals are larger than the native protein, apparently deriving from increased ordering of the N-terminus and an internal loop (residues 495-500) in subunit I. Hence, compared with native cytochrome ba(3) oxidase, the recombinant His-tagged protein is accommodated in an expanded but equally well ordered lattice via an alternate set of specific intermolecular contacts. The structure was refined against data to 2.3 angstroms resolution to an R factor of 21.7% and an R(free) of 23.7%.

About this StructureAbout this Structure

2QPE is a Protein complex structure of sequences from Thermus thermophilus with , , and as ligands. Active as Cytochrome-c oxidase, with EC number 1.9.3.1 Full crystallographic information is available from OCA.

ReferenceReference

A novel cryoprotection scheme for enhancing the diffraction of crystals of recombinant cytochrome ba3 oxidase from Thermus thermophilus., Hunsicker-Wang LM, Pacoma RL, Chen Y, Fee JA, Stout CD, Acta Crystallogr D Biol Crystallogr. 2005 Mar;61(Pt 3):340-3. Epub 2005, Feb 24. PMID:15735345

Page seeded by OCA on Thu Feb 21 18:41:06 2008

Proteopedia Page Contributors and Editors (what is this?)Proteopedia Page Contributors and Editors (what is this?)

OCA

@@ Line 4: / Line 4: @@
 ==Overview==
-Cytochrome ba(3) oxidase is an integral membrane protein identified in the, thermophilic bacterium Thermus thermophilus. The enzyme has now been, expressed recombinantly and purified with a histidine tag. As such, it, crystallizes under similar conditions and in the same space group, (P4(3)2(1)2) as the native protein. A novel cryoprotection scheme is, described here to obtain high-resolution diffraction from these crystals, which involves soaking in a mixture of glycerol and ethylene glycol under, a layer of oil. The unit-cell parameters for these crystals are larger, than the native protein, apparently deriving from increased ordering of, the N-terminus and an internal loop (residues 495-500) in subunit I., Hence, compared with native cytochrome ba(3) oxidase, the recombinant, His-tagged protein is accommodated in an expanded but equally well ordered, lattice via an alternate set of specific intermolecular contacts. The, structure was refined against data to 2.3 angstroms resolution to an R, factor of 21.7% and an R(free) of 23.7%.
+Cytochrome ba(3) oxidase is an integral membrane protein identified in the thermophilic bacterium Thermus thermophilus. The enzyme has now been expressed recombinantly and purified with a histidine tag. As such, it crystallizes under similar conditions and in the same space group (P4(3)2(1)2) as the native protein. A novel cryoprotection scheme is described here to obtain high-resolution diffraction from these crystals, which involves soaking in a mixture of glycerol and ethylene glycol under a layer of oil. The unit-cell parameters for these crystals are larger than the native protein, apparently deriving from increased ordering of the N-terminus and an internal loop (residues 495-500) in subunit I. Hence, compared with native cytochrome ba(3) oxidase, the recombinant His-tagged protein is accommodated in an expanded but equally well ordered lattice via an alternate set of specific intermolecular contacts. The structure was refined against data to 2.3 angstroms resolution to an R factor of 21.7% and an R(free) of 23.7%.
 ==About this Structure==
@@ Line 15: / Line 15: @@
 [[Category: Thermus thermophilus]]
 [[Category: Chen, Y.]]
-[[Category: Fee, J.A.]]
+[[Category: Fee, J A.]]
 [[Category: Liu, B.]]
-[[Category: Luna, V.M.]]
+[[Category: Luna, V M.]]
-[[Category: Stout, C.D.]]
+[[Category: Stout, C D.]]
 [[Category: CU1]]
 [[Category: CUA]]
@@ Line 38: / Line 38: @@
 [[Category: transport]]
-''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Wed Jan 23 11:44:53 2008''
+''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 18:41:06 2008''