Department of Medical Microbiology, Section Experimental Bacteriology, Leiden University Medical Center, Leiden, the Netherlands; Center for Microbial Cell Biology, Leiden, the Netherlands.
Faculty of Science, Leiden Institute of Chemistry, Leiden University, Leiden, the Netherlands; Center for Microbial Cell Biology, Leiden, the Netherlands.
J Mol Biol. 2019 Feb 15;431(4):653-672. doi: 10.1016/j.jmb.2019.01.001. Epub 2019 Jan 8.
The maintenance and organization of the chromosome plays an important role in the development and survival of bacteria. Bacterial chromatin proteins are architectural proteins that bind DNA and modulate its conformation, and by doing so affect a variety of cellular processes. No bacterial chromatin proteins of Clostridium difficile have been characterized to date. Here, we investigate aspects of the C. difficile HupA protein, a homologue of the histone-like HU proteins of Escherichia coli. HupA is a 10-kDa protein that is present as a homodimer in vitro and self-interacts in vivo. HupA co-localizes with the nucleoid of C. difficile. It binds to the DNA without a preference for the DNA G + C content. Upon DNA binding, HupA induces a conformational change in the substrate DNA in vitro and leads to compaction of the chromosome in vivo. The present study is the first to characterize a bacterial chromatin protein in C. difficile and opens the way to study the role of chromosomal organization in DNA metabolism and on other cellular processes in this organism.
染色体的维持和组织在细菌的发育和生存中起着重要作用。细菌染色质蛋白是一种结构蛋白，它结合 DNA 并调节其构象，从而影响多种细胞过程。迄今为止，尚未对艰难梭菌的任何染色质蛋白进行表征。在这里，我们研究了艰难梭菌 HupA 蛋白的一些方面，该蛋白是大肠杆菌组蛋白样 HU 蛋白的同源物。HupA 是一种 10kDa 的蛋白质，在体外以同源二聚体的形式存在，并在体内相互作用。HupA 与艰难梭菌的核体共定位。它与 DNA 结合，而不偏爱 DNA 的 G + C 含量。在 DNA 结合后，HupA 在体外诱导底物 DNA 的构象变化，并导致染色体在体内的紧缩。本研究首次对艰难梭菌中的细菌染色质蛋白进行了表征，并为研究染色体组织在该生物体的 DNA 代谢和其他细胞过程中的作用开辟了道路。
