Knight A E, Kendrick-Jones J
MRC Laboratory of Molecular Biology, Cambridge, U.K.
J Mol Biol. 1993 May 5;231(1):148-54. doi: 10.1006/jmbi.1993.1266.
As part of a study of the diversity of myosins, we have cloned a cDNA encoding a myosin-like protein from Arabidopsis thaliana. This is the first molecular motor of any kind to be cloned from a higher plant. The predicted polypeptide (molecular weight 131 kDa) has a motor domain (head) very similar to those of other myosins, but the remainder of the sequence is unusual. The tail contains four potential calmodulin binding sites ("IQ-motifs"), but no sequence motifs suggestive of actin or phospholipid binding, like those found in other myosins. There is also a small region of probable alpha-helical coiled-coil, which suggests that the molecule could be dimeric, though unlikely to form filaments. The N-terminal and C-terminal regions of the molecule are unique. We present a phylogenetic analysis of myosin head sequences, which suggests that this is a new type of myosin.
作为对肌球蛋白多样性研究的一部分，我们从拟南芥中克隆了一个编码类肌球蛋白蛋白的cDNA。这是从高等植物中克隆出的首个任何类型的分子马达。预测的多肽（分子量131 kDa）具有一个与其他肌球蛋白非常相似的马达结构域（头部），但其序列的其余部分并不寻常。尾部含有四个潜在的钙调蛋白结合位点（“IQ模体”），但没有像其他肌球蛋白中发现的那些提示肌动蛋白或磷脂结合的序列模体。还有一个可能是α-螺旋卷曲螺旋的小区域，这表明该分子可能是二聚体，尽管不太可能形成细丝。该分子的N端和C端区域是独特的。我们对肌球蛋白头部序列进行了系统发育分析，结果表明这是一种新型的肌球蛋白。
