Singh Gurjeet, Klar Amar J S
Gene Regulation and Chromosome Biology Laboratory, National Cancer Institute at Frederick, Frederick, MD 21702-1201, USA.
Yeast. 2003 Nov;20(15):1273-8. doi: 10.1002/yea.1042.
To define conserved sequences for mat1 imprinting and silencing of the mat2,3 region of Schizosaccharomyces pombe, we determined the DNA sequence of the cognate region (mat2,3 region) of another fission yeast, Sz. kambucha, a yeast species isolated from Kambucha tea mix. The entire mat2,3 region shows more than 98% identity between the two species. Sequence similarity is even higher (99.3%) for mating-type cassettes; deduced amino acid sequences of three of the four Mat peptides (Pi, Pc and Mi) are identical between the two species, while the fourth (Mc) has a single amino acid polymorphism. Comparison of the sequence motif of the imprint site essential for mat1 switching shows that mat-P of Sz. kambucha has a sequence identical to the conserved motif present in Sz. pombe. However, this sequence motif of nine bases differs by one base for mat-M of Sz. kambucha. The sequence of the K region shows about 98% identity between the two species, with the cenH region showing 98.3% homology. Thus, the arrangement of the mat2,3 region in both yeasts is conserved and shows 1-2% nucleotide sequence variation throughout the region. The DNA sequence of the mat2,3 region from Sz. kambucha has been submitted to GenBank under Accession No. AY271822.
为了确定粟酒裂殖酵母mat1印记以及mat2、3区域沉默的保守序列，我们测定了另一种裂殖酵母——从康普茶混合物中分离出的酵母物种坎布茶裂殖酵母同源区域（mat2、3区域）的DNA序列。两个物种的整个mat2、3区域显示出超过98%的同一性。交配型盒的序列相似性更高（99.3%）；两种物种中四个Mat肽（Pi、Pc和Mi）中的三个推导氨基酸序列相同，而第四个（Mc）有一个单氨基酸多态性。对mat1转换所必需的印记位点序列基序的比较表明，坎布茶裂殖酵母的mat-P具有与粟酒裂殖酵母中存在的保守基序相同的序列。然而，坎布茶裂殖酵母的mat-M的这个九个碱基的序列基序有一个碱基不同。K区域的序列在两个物种之间显示出约98%的同一性，着丝粒H区域显示出98.3%的同源性。因此，两种酵母中mat2、3区域的排列是保守的，并且在整个区域显示出1-2%的核苷酸序列变异。坎布茶裂殖酵母mat2、3区域的DNA序列已以登录号AY271822提交至GenBank。
