DsaV甲基转移酶及其同裂酶包含一个保守区段，该保守区段与Hhai甲基转移酶中与DNA碱基接触的区段相似。

DsaV methyltransferase and its isoschizomers contain a conserved segment that is similar to the segment in Hhai methyltransferase that is in contact with DNA bases.

作者信息

Gopal J, Yebra M J, Bhagwat A S

机构信息

Department of Chemistry, Wayne State University, Detroit, MI 48202.

出版信息

Nucleic Acids Res. 1994 Oct 25;22(21):4482-8. doi: 10.1093/nar/22.21.4482.

DOI:10.1093/nar/22.21.4482

PMID:7971279

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC308483/

Abstract

The methyltransferase (MTase) in the DsaV restriction--modification system methylates within 5'-CCNGG sequences. We have cloned the gene for this MTase and determined its sequence. The predicted sequence of the MTase protein contains sequence motifs conserved among all cytosine-5 MTases and is most similar to other MTases that methylate CCNGG sequences, namely M.ScrFI and M.SsoII. All three MTases methylate the internal cytosine within their recognition sequence. The 'variable' region within the three enzymes that methylate CCNGG can be aligned with the sequences of two enzymes that methylate CCWGG sequences. Remarkably, two segments within this region contain significant similarity with the region of M.HhaI that is known to contact DNA bases. These alignments suggest that many cytosine-5 MTases are likely to interact with DNA using a similar structural framework.

摘要

DsaV 限制 - 修饰系统中的甲基转移酶（MTase）在 5'-CCNGG 序列内进行甲基化。我们已克隆了该 MTase 的基因并确定了其序列。MTase 蛋白的预测序列包含在所有胞嘧啶 -5 甲基转移酶中保守的序列基序，并且与其他甲基化 CCNGG 序列的 MTase 最为相似，即 M.ScrFI 和 M.SsoII。所有这三种 MTase 都在其识别序列内甲基化内部胞嘧啶。甲基化 CCNGG 的三种酶中的“可变”区域可以与甲基化 CCWGG 序列的两种酶的序列对齐。值得注意的是，该区域内的两个片段与已知与 DNA 碱基接触的 M.HhaI 区域具有显著相似性。这些比对表明，许多胞嘧啶 -5 甲基转移酶可能使用相似的结构框架与 DNA 相互作用。