|2qpe, resolution 2.90Å ()|
|Ligands:||, , ,|
|Gene:||cbaA (Thermus thermophilus), cbaB, ctaC (Thermus thermophilus), cbaD (Thermus thermophilus)|
An unexpected outcome of surface-engineering an integral membrane protein: Improved crystallization of cytochrome ba3 oxidase from Thermus thermophilus
Past work has shown that it is feasible to mutate surface residues of soluble proteins and to a lesser extent membrane proteins in order to improve their crystallization behavior. Described here is a successful application of this approach to the integral membrane protein Thermus thermophilus cytochrome ba(3) oxidase. Two mutant forms of this enzyme (I-K258R and I-K258R/II-E4Q) were created in which symmetrical crystal contacts within crystals of wild-type enzyme were modified. These mutant proteins had greatly shortened crystallization times, decreasing from approximately 30 d for the wild type to 1-3 d for the mutants, and crystallization was highly reproducible. Native-like proteins crystallize in space group P4(3)2(1)2, whereas the mutant proteins crystallize in space group P4(1)2(1)2 with a different packing arrangement. Crystals of the P4(3)2(1)2 form occasionally diffracted to 2.4-2.3 A resolution following controlled dehydration, while those of the P4(1)2(1)2 form routinely diffracted to between 3.0 and 2.6 A for crystals that had been cryoprotected but not dehydrated.
An unexpected outcome of surface engineering an integral membrane protein: improved crystallization of cytochrome ba(3) from Thermus thermophilus., Liu B, Luna VM, Chen Y, Stout CD, Fee JA, Acta Crystallogr Sect F Struct Biol Cryst Commun. 2007 Dec 1;63(Pt, 12):1029-34. Epub 2007 Nov 21. PMID:18084085
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
About this Structure
- Liu B, Luna VM, Chen Y, Stout CD, Fee JA. An unexpected outcome of surface engineering an integral membrane protein: improved crystallization of cytochrome ba(3) from Thermus thermophilus. Acta Crystallogr Sect F Struct Biol Cryst Commun. 2007 Dec 1;63(Pt, 12):1029-34. Epub 2007 Nov 21. PMID:18084085 doi:10.1107/S1744309107054176
- Chen Y, Hunsicker-Wang L, Pacoma RL, Luna E, Fee JA. A homologous expression system for obtaining engineered cytochrome ba3 from Thermus thermophilus HB8. Protein Expr Purif. 2005 Apr;40(2):299-318. PMID:15766872 doi:10.1016/j.pep.2004.11.014