密螺旋体中特定于GATC的限制与修饰系统。

GATC-specific restriction and modification systems in treponemes.

作者信息

Piknova M, Pristas P, Javorsky P, Kasperowic A, Michalowski T

机构信息

Faculty of Science, Institute of Chemistry, P. J. Safarik University, Moyzesova, Kosice, Slovakia.

出版信息

Lett Appl Microbiol. 2004;38(4):311-4. doi: 10.1111/j.1472-765x.2004.01483.x.

DOI:10.1111/j.1472-765x.2004.01483.x

PMID:15214731

Abstract

AIMS

To investigate the presence of GATC-specific modification and restriction activities in rumen isolates of Treponema sp.

METHODS

The presence of N6-methyladenine within GATC (Dam) sequences was analysed using isoschizomeric restriction endonucleases having different sensitivities to the methylation of the target sequence. A fast screening method was used for testing of site-specific endonuclease activities directly in crude cell extracts. Three out of six rumen isolates of Treponema sp. showed restriction activities. Restriction endonucleases were further purified by Heparin-Sepharose chromatography. Using PCR and specific primers, no sequence homologous to the T. pallidum dam gene was found.

CONCLUSIONS

Three rumen treponemal strains were documented to possess MboI isoschizomeric restriction-modification systems.

SIGNIFICANCE

This is the first report on restriction activity in rumen treponemes.

摘要

目的

研究密螺旋体属瘤胃分离株中GATC特异性修饰和限制活性的存在情况。

方法

使用对靶序列甲基化具有不同敏感性的同裂酶限制性内切核酸酶分析GATC（Dam）序列内N6-甲基腺嘌呤的存在情况。采用一种快速筛选方法直接在粗细胞提取物中检测位点特异性内切核酸酶活性。六株瘤胃密螺旋体属分离株中有三株显示出限制活性。通过肝素-琼脂糖层析进一步纯化限制性内切核酸酶。使用聚合酶链反应（PCR）和特异性引物，未发现与梅毒密螺旋体dam基因同源的序列。