日本研究人員在新一期《科學(xué)》雜志網(wǎng)絡(luò)版發(fā)表的研究結(jié)果顯示,，幽門螺桿菌等病原菌和乳酸菌等益生菌合成呼吸所需維生素的機(jī)制完全不同。
日本富山縣立大學(xué)副教授大利徹等人介紹說(shuō),，他們解析了多種微生物的基因組后新發(fā)現(xiàn)了病原菌共有的4個(gè)基因，這些基因的功能都是編碼合成病原菌呼吸所需的維生素,。研究人員進(jìn)一步分析了這4個(gè)基因,，并將病原菌和益生菌合成呼吸所需維生素的過(guò)程進(jìn)行了對(duì)比。結(jié)果發(fā)現(xiàn),，雖然病原菌和益生菌合成維生素所用的原料相同,，但這些原料經(jīng)過(guò)完全不同的化學(xué)變化，最終形成了維生素,。
幽門螺桿菌與胃癌等的發(fā)病密切相關(guān),，目前針對(duì)幽門螺桿菌的除菌藥物會(huì)把腸道內(nèi)對(duì)人體有益的益生菌一道殺滅，有引發(fā)腹瀉、腹痛等副作用,。研究人員說(shuō),，以新發(fā)現(xiàn)為基礎(chǔ)，將來(lái)也許可以通過(guò)基因操作除去病原菌,，同時(shí)又不“誤殺”益生菌。（生物谷Bioon.com）
生物谷推薦原始出處：
Science 19 September 2008: Vol. 321. no. 5896, pp. 1670 - 1673 DOI: 10.1126/science.1160446
An Alternative Menaquinone Biosynthetic Pathway Operating in Microorganisms
Tomoshige Hiratsuka,1 Kazuo Furihata,2 Jun Ishikawa,3 Haruyuki Yamashita,4 Nobuya Itoh,1 Haruo Seto,5Tohru Dairi1*
In microorganisms, menaquinone is an obligatory component of the electron-transfer pathway. It is derived from chorismate by seven enzymes in Escherichia coli. However, a bioinformatic analysis of whole genome sequences has suggested that some microorganisms, including pathogenic species such as Helicobacter pylori andCampylobacter jejuni, do not have orthologs of the men genes, even though they synthesize menaquinone. We deduced the outline of this alternative pathway in a nonpathogenic strain of Streptomyces by bioinformatic screening, gene knockouts, shotgun cloning with isolated mutants, and in vitro studies with recombinant enzymes. As humans and commensal intestinal bacteria, including lactobacilli, lack this pathway, it represents an attractive target for the development of chemotherapeutics.
1 Biotechnology Research Center, Toyama Prefectural University, Toyama 939-0398, Japan.
2 Division of Agriculture and Agricultural Life Science, The University of Tokyo, Bunkyo-ku, Tokyo 113-8657 Japan.
3 Department of Bioactive Molecules, National Institute of Infectious Diseases, Shinjuku-ku, Tokyo 162-8640, Japan.
4 Advanced Materials Research and Development Laboratory, ADEKA Corporation, Arakawa-ku, Tokyo 116-8553, Japan.
5 Faculty of Applied Bioscience, Tokyo University of Agriculture, Setagaya-ku, Tokyo 156-8502, Japan.
