Yumoto Fumiaki, Nagata Koji, Miyauchi Yumiko, Ojima Takao, Tanaka Hiroyuki, Nishita Kiyoyoshi, Ohtsuki Iwao, Tanokura Masaru
Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, Bunkyo-ku, Tokyo, Japan.
Acta Crystallogr Sect F Struct Biol Cryst Commun. 2007 Jun 1;63(Pt 6):535-7. doi: 10.1107/S1744309107024712. Epub 2007 May 31.
Troponin C (TnC) is the Ca(2+)-binding component of troponin and triggers muscle contraction. TnC of the invertebrate Akazara scallop can bind only one Ca(2+) at the C-terminal EF-hand motif. Recombinant TnC was expressed in Escherichia coli, purified, complexed with a 24-residue synthetic peptide derived from scallop troponin I (TnI) and crystallized. The crystals diffracted X-rays to 1.80 A resolution and belonged to space group P2(1)2(1)2(1), with unit-cell parameters a = 32.1, b = 42.2, c = 60.0 A. The asymmetric unit was assumed to contain one molecular complex of the Akazara scallop TnC C-lobe and TnI fragment, with a Matthews coefficient of 1.83 A(3) Da(-1) and a solvent content of 33.0%.
肌钙蛋白C（TnC）是肌钙蛋白的钙结合成分，可触发肌肉收缩。无脊椎动物赤坂扇贝的TnC在C端EF-手基序处只能结合一个Ca(2+)。重组TnC在大肠杆菌中表达、纯化，与源自扇贝肌钙蛋白I（TnI）的24个残基的合成肽复合并结晶。晶体的X射线衍射分辨率为1.80 Å，属于空间群P2(1)2(1)2(1)，晶胞参数a = 32.1、b = 42.2、c = 60.0 Å。假定不对称单元包含一个赤坂扇贝TnC C叶和TnI片段的分子复合物，马修斯系数为1.83 Å(3) Da(-1)，溶剂含量为33.0%。
