Wolfe K H, Lohan A J
Department of Genetics, University of Dublin, Trinity College, Ireland.
Yeast. 1994 Apr;10 Suppl A:S41-6. doi: 10.1002/yea.320100006.
We report the sequence of a 12 kilobase region spanning the centromere of Saccharomyces cerevisiae chromosome II. The sequence from the left arm includes genes for histones H2A and H2B. The sequence from the right arm includes a gene that probably encodes a novel trehalase, as well as the COQ1 gene (for an enzyme involved in coenzyme Q biosynthesis), and an open reading frame with significant similarity to bacterial genes of unknown function. The trehalase gene (YBR0106) on chromosome II is located beside the centromere and transcribed towards it. This is identical to the arrangement of the neutral trehalase gene (NTH1) beside the centromere of chromosome IV. The centromere regions of chromosomes II and IV may therefore have arisen through a duplication of the centromere region of an ancestral chromosome. The YBR0106 and NTH1 proteins are 77% identical in predicted amino acid sequence, but there is no pronounced sequence similarity between the two centromeres (CEN2 and CEN4) outside of the universally conserved CDE I and CDE III elements. The genes flanking the centromere and trehalase genes differ between the two chromosomes, so the similarity between chromosomes II and IV may be less extensive than that recently reported between chromosomes III and XIV.
我们报道了酿酒酵母二号染色体着丝粒区域一个12千碱基的序列。左臂的序列包含组蛋白H2A和H2B的基因。右臂的序列包含一个可能编码新型海藻糖酶的基因，以及COQ1基因（参与辅酶Q生物合成的一种酶），还有一个与功能未知的细菌基因有显著相似性的开放阅读框。二号染色体上的海藻糖酶基因（YBR0106）位于着丝粒旁边并朝着着丝粒转录。这与四号染色体着丝粒旁边的中性海藻糖酶基因（NTH1）的排列方式相同。因此，二号和四号染色体的着丝粒区域可能是通过一条祖先染色体着丝粒区域的重复产生的。YBR0106和NTH1蛋白在预测的氨基酸序列上有77%的同一性，但在普遍保守的CDE I和CDE III元件之外，两个着丝粒（CEN2和CEN4）之间没有明显的序列相似性。两条染色体上着丝粒两侧的基因以及海藻糖酶基因有所不同，所以二号和四号染色体之间的相似性可能不如最近报道的三号和十四号染色体之间的相似性那么广泛。
