X-ray crystal analysis of a TASP: structural insights of a cavitein dimer.
Cavitein Q4 is a template assembled synthetic protein designed for X-ray crystallographic analysis. It is based on a previous monomeric helical bundle cavitein (N1GG) that consists of four identical parallel helical peptides. Crystals that were grown in the presence of bromide ions were used to solve the initial phases via single-wavelength anomalous dispersion (SAD). A 1.4 A resolution data set was then refined starting with the SAD phases to provide the crystal structure of cavitein Q4. The crystal structure revealed cavitein Q4 as an asymmetric dimer, although the cavitein appears to be largely monomeric in solution. A comparative analysis is carried out to discern any intrinsic differences between Q4 and its parent cavitein N1GG. We present herein the first X-ray crystal structure of a TASP system and relate this structure to the solution data for both Q4 and its parent N1GG.
Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, BC, Canada V6T 1Z1.
Jon O
JO
Freeman
Woo Cheol
WC
Lee
Michael E P
ME
Murphy
John C
JC
Sherman
D003460:Crystallization; D018360:Crystallography, X-Ray; D010455:Peptides; D015202:Protein Engineering / Q000379:methods*; D011506:Proteins / Q000138:chemical synthesis / Q000737:chemistry*
D010455:Peptides; D011506:Proteins