Open AccessCloning, expression, purification, crystallization and preliminary crystallographic analysis of selenomethionine‐labelled KaiC‐like protein PH0186 from Pyrococcus horikoshii OT3
Author(s) -
Ming Hua,
Miyazono Kenichi,
Tanokura Masaru
Publication year - 2007
Publication title -
acta crystallographica section f
Language(s) - English
Resource type - Journals
ISSN - 1744-3091
DOI - 10.1107/s1744309107011402
Subject(s) - pyrococcus horikoshii , random hexamer , crystallography , crystallization , crystal (programming language) , protein crystallization , materials science , crystal structure , chemistry , organic chemistry , computer science , programming language
KaiC is the central protein in the circadian‐clock system of cyanobacteria. A selenomethionine‐labelled KaiC‐homologous protein from Pyrococcus horikoshii OT3 (PH0186; 28 kDa) was crystallized by the sitting‐drop vapour‐diffusion method using ethanol as a precipitant. The crystals diffracted X‐rays to beyond 2.0 Å resolution using a synchrotron‐radiation source. The space group of the crystals was determined to be C 2, with unit‐cell parameters a = 173.7, b = 51.8, c = 97.5 Å, β = 122.8°. The crystal contains three molecules in the asymmetric unit ( V M = 2.2 Å 3 Da −1 ) and has a solvent content of 43.5%. Sixfold noncrystallographic symmetry was identified from self‐rotation calculations, assuming the presence of a hexamer in the crystal.