Song Y, Kim S, Kim J
Department of Microbiology, College of Natural Sciences, Chungnam National University, Daejeon, South Korea.
Gene. 1995 Dec 1;166(1):151-4. doi: 10.1016/0378-1119(96)80010-2.
The KEM1 gene is involved in nuclear fusion during conjugation, and chromosome transmission and spindle pole body duplication/or separation during mitotic cell division in the yeast Saccharomyces cerevisiae. KEM1 was also independently identified as DST2, SEP1, XRN1 and RAR5 on the basis of DNA strand transferase or exoribonuclease activity in vitro or mutations affecting plasmid stability. To understand the various functions suggested for KEM1 and to identify other genes with functions similar or related to those of KEM1, we have characterized the ROK1 gene which was isolated as a high-copy-number plasmid suppressor of the kem1 null mutation. Sequence analysis of the smallest subclone with the suppression activity revealed an open reading frame of 564 amino acids. The ROK1 aa sequence contains highly conserved domains found in the DEAD protein family of ATP-dependent RNA helicases. ROK1 is essential for viability and is closely linked to KEM1 on chromosome VII.
KEM1基因参与酿酒酵母接合过程中的核融合，以及有丝分裂细胞分裂过程中的染色体传递和纺锤体极体复制/分离。基于体外DNA链转移酶或外切核糖核酸酶活性或影响质粒稳定性的突变，KEM1还被分别鉴定为DST2、SEP1、XRN1和RAR5。为了了解KEM1所暗示的各种功能，并鉴定与KEM1功能相似或相关的其他基因，我们对ROK1基因进行了表征，该基因是作为kem1缺失突变的高拷贝数质粒抑制子分离得到的。对具有抑制活性的最小亚克隆进行序列分析，发现了一个由564个氨基酸组成的开放阅读框。ROK1氨基酸序列包含在依赖ATP的RNA解旋酶的DEAD蛋白家族中发现的高度保守结构域。ROK1对细胞活力至关重要，并且与VII号染色体上的KEM1紧密连锁。
