1hlu
From Proteopedia
STRUCTURE OF BOVINE BETA-ACTIN-PROFILIN COMPLEX WITH ACTIN BOUND ATP PHOSPHATES SOLVENT ACCESSIBLE
Overview
The structure of an "open state" of crystalline profilin:beta-actin has been solved to 2.65 A by X-ray crystallography. The open-state crystals, in 1.8 M potassium phosphate, have an expanded unit cell dimension in the c direction of 185.7 A compared with 171.9 A in the previously solved ammonium sulphate-stabilized "tight-state" structure. The unit cell change between the open and the tight states is accompanied by large subdomain movements in actin. Furthermore, the nucleotide in the open state is significantly more exposed to solvent, and local conformational changes in the hydrophobic pocket surrounding cysteine 374 occur during the transition to the tight state. Significant changes were observed at the N terminus and in the DNase-I binding loop. Neither the structure of profilin nor its contact with beta-actin are affected by the changes in the unit cell. Applying osmotic pressure to profilin:beta-actin crystals brings about a collapse of the unit cell comparable with that seen in the open to tight-state transition, enabling an estimate of the work required to cause this transformation of beta-actin in the crystals. The slight difference in energy between the open and collapsed states explains the extreme sensitivity of profilin:beta-actin crystals to changes in chemical and thermal environment.
About this Structure
1HLU is a Protein complex structure of sequences from Bos taurus. The following page contains interesting information on the relation of 1HLU with [Actin]. Full crystallographic information is available from OCA.
Reference
The structure of an open state of beta-actin at 2.65 A resolution., Chik JK, Lindberg U, Schutt CE, J Mol Biol. 1996 Nov 8;263(4):607-23. PMID:8918942 Page seeded by OCA on Fri May 2 18:59:28 2008
