Lee Bo-Rahm, Yi Da-Hye, Song Eunjung, Bhatia Shashi Kant, Lee Ju Hee, Kim Yun-Gon, Park Sung-Hee, Lee Yoo Kyung, Kim Byung-Gee, Yang Yung-Hun
School of Chemical and Biological Engineering, Seoul National University, Kwanak-Gu, 151-742, Seoul, Korea.
Appl Biochem Biotechnol. 2015 Apr;175(8):3673-82. doi: 10.1007/s12010-015-1536-z. Epub 2015 Feb 18.
The antibiotic production and spore formation process in Streptomyces coelicolor need complex decision making processes by several regulatory units. These regulatory units are involved in both primary and secondary metabolism. As a result, most regulators have several functions, and those are worthwhile themes to study about different functions of a known regulator. In this study, a deletion mutant of ndgR, which encodes the nitrogen-dependent growth regulator, was examined by the cell viability test, TEM, and growth in N-acetylglucosamine/asparagine (GlcNAc/Asn) liquid medium. The results of the study show that NdgR is also involved in the structure of the cell membrane affecting survival under physical shocks. Deletion of ndgR leads to abnormal cell membrane resulting in the vulnerable cells to physical stress caused by shaking with beads in liquid culture condition. This empirical observation is the first meaningful explanation to why ndgR mutant could not grow well in a liquid minimal medium due to the defect of N-acetylglucosamine (GlcNAc) utilization and phospholipid synthesis.
天蓝色链霉菌中的抗生素生产和孢子形成过程需要几个调控单元进行复杂的决策过程。这些调控单元参与初级和次级代谢。因此，大多数调控因子具有多种功能，而这些都是研究已知调控因子不同功能的有价值的主题。在本研究中，通过细胞活力测试、透射电子显微镜（TEM）以及在N-乙酰葡糖胺/天冬酰胺（GlcNAc/Asn）液体培养基中的生长情况，对编码氮依赖性生长调控因子的ndgR缺失突变体进行了检测。研究结果表明，NdgR还参与细胞膜结构，影响细胞在物理冲击下的存活。ndgR的缺失导致细胞膜异常，使细胞在液体培养条件下与珠子振荡引起的物理应激中变得脆弱。这一经验性观察结果首次对ndgR突变体由于N-乙酰葡糖胺（GlcNAc）利用和磷脂合成缺陷而无法在液体基本培养基中良好生长的原因给出了有意义的解释。
