2RJT

Crystal Structure Analysis of a Surface Entropy Reduction Mutant of S. pneumoniae FabF

Summary for 2RJT

• Entry DOI: 10.2210/pdb2rjt/pdb
• Descriptor: Beta-ketoacyl-ACP synthase II (2 entities in total)
• Functional Keywords: kasii, beta-ketoacyl acyl carrier protein synthase, thiolase, fabf, acyltransferase, transferase
• Biological source: Streptococcus pneumoniae
• Total number of polymer chains: 4
• Total formula weight: 181828.30

Authors

Soisson, S.M.,Parthasarathy, G.,Becker, J. (deposition date: 2007-10-15, release date: 2008-01-22, Last modification date: 2024-02-21)

Primary citation

Parthasarathy, G.,Cummings, R.,Becker, J.W.,Soisson, S.M.
Surface-entropy reduction approaches to manipulate crystal forms of beta-ketoacyl acyl carrier protein synthase II from Streptococcus pneumoniae.
Acta Crystallogr.,Sect.D, 64:141-148, 2008

PubMed Abstract: A series of experiments with beta-ketoacyl acyl carrier protein synthase II (FabF) from Streptococcus pneumonia (spFabF) were undertaken to evaluate the capability of surface-entropy reduction (SER) to manipulate protein crystallization. Previous work has shown that this protein crystallizes in two forms. The triclinic form contains four molecules in the asymmetric unit (a.u.) and diffracts to 2.1 A resolution, while the more desirable primitive orthorhombic form contains one molecule in the a.u. and diffracts to 1.3 A. The aim was to evaluate the effect of SER mutations that were specifically engineered to avoid perturbing the crystal-packing interfaces employed by the favorable primitive orthorhombic crystal form while potentially disrupting a surface of the protein employed by the less desirable triclinic crystal form. Two mutant proteins were engineered, each of which harbored five SER mutations. Extensive crystallization screening produced crystals of the two mutants, but only under conditions that differed from those used for the native protein. One of the mutant proteins yielded crystals that were of a new form (centered orthorhombic), despite the fact that the interfaces employed by the primitive orthorhombic form of the native protein were specifically unaltered. Structure determination at 1.75 A resolution reveals that one of the mutations, E383A, appears to play a key role in disfavouring the less desirable triclinic crystal form and in generating a new surface for a packing interaction that stabilizes the new crystal form.

PubMed: 18219113
DOI: 10.1107/S090744490705559X

Experimental method

X-RAY DIFFRACTION (1.75 Å)