1fcl
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DELTA1.5: A COMPUTATIONALLY DESIGNED CORE VARIANT OF THE B1 DOMAIN OF STREPTOCOCCAL PROTEIN G
OverviewOverview
The solution structures of two computationally designed core variants of, the beta 1 domain of streptococcal protein G (G beta 1) were solved by, (1)H NMR methods to assess the robustness of amino acid sequence selection, by the ORBIT protein design package under changes in protein backbone, specification. One variant has mutations at three of 10 core positions and, corresponds to minimal perturbations of the native G beta 1 backbone. The, other, with mutations at six of 10 positions, was calculated for a, backbone in which the separation between G beta 1's alpha-helix and, beta-sheet was increased by 15% relative to native G beta 1. Exchange, broadening of some resonances and the complete absence of others in, spectra of the sixfold mutant bespeak conformational heterogeneity in this, protein. The NMR data were sufficiently abundant, however, to generate, structures of similar, moderately high quality for both variants. Both, proteins adopt backbone structures similar to their target folds., Moreover, the sequence selection algorithm successfully predicted all core, chi(1) angles in both variants, five of six chi(2) angles in the threefold, mutant and four of seven chi(2) angles in the sixfold mutant. We conclude, that ORBIT calculates sequences that fold specifically to a geometry close, to the template, even when the template is moderately perturbed relative, to a naturally occurring structure. There are apparently limits to the, size of acceptable perturbations: In this study, the larger perturbation, led to undesired dynamic behavior.
About this StructureAbout this Structure
1FCL is a Single protein structure of sequence from Streptococcus sp.. Full crystallographic information is available from OCA.
ReferenceReference
Designed protein G core variants fold to native-like structures: sequence selection by ORBIT tolerates variation in backbone specification., Ross SA, Sarisky CA, Su A, Mayo SL, Protein Sci. 2001 Feb;10(2):450-4. PMID:11266631
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