Query C C, Bentley R C, Keene J D
Department of Microbiology and Immunology, Duke University Medical Center, Durham, North Carolina 27710.
Cell. 1989 Apr 7;57(1):89-101. doi: 10.1016/0092-8674(89)90175-x.
We have defined the RNA binding domain of the 70K protein component of the U1 small nuclear ribonucleoprotein to a region of 111 amino acids. This domain encompasses an octamer sequence that has been observed in other proteins associated with RNA, but has not previously been shown to bind directly to a specific RNA sequence. Within the U1 RNA binding domain, an 80 amino acid consensus sequence that is conserved in many presumed RNA binding proteins was discerned. This sequence pattern appears to represent an RNA recognition motif (RRM) characteristic of a distinct family of proteins. By site-directed mutagenesis, we determined that the 70K protein consists of 437 amino acids (52 kd), and found that its aberrant electrophoretic migration is due to a carboxy-terminal charged domain structurally similar to two Drosophila proteins (su(wa) and tra) that may regulate alternative pre-messenger RNA splicing.
我们已将U1小核核糖核蛋白70K蛋白组分的RNA结合结构域定位至一个由111个氨基酸组成的区域。该结构域包含一个八聚体序列，此序列在其他与RNA相关的蛋白质中也有发现，但此前尚未证明它能直接结合特定的RNA序列。在U1 RNA结合结构域内，识别出一个在许多假定的RNA结合蛋白中保守的80个氨基酸的共有序列。这种序列模式似乎代表了一类独特蛋白质家族所特有的RNA识别基序（RRM）。通过定点诱变，我们确定70K蛋白由437个氨基酸（52kd）组成，并发现其异常的电泳迁移是由于其羧基末端的带电结构域，该结构域在结构上与两种果蝇蛋白（su(wa)和tra）相似，这两种蛋白可能调节前体信使RNA的可变剪接。
