Buerger Julia, Rehm Nadine, Grebenstein Laura, Burkovski Andreas
Department of Biology, Microbiology Division, Friedrich-Alexander-University Erlangen-Nuremberg, Erlangen, Germany.
Department of Biology, Microbiology Division, Friedrich-Alexander-University Erlangen-Nuremberg, Erlangen, Germany
FEMS Microbiol Lett. 2016 Oct;363(20). doi: 10.1093/femsle/fnw230. Epub 2016 Oct 7.
Corynebacterium glutamicum is able to metabolize different nitrogen and carbon sources. In standard minimal media, ammonium and urea typically serve as nitrogen source and glucose or sucrose as carbon and energy source; however, amino acids might also play a role as nitrogen, carbon and energy source. In this study, the function of the putative glutaminase GlsK was investigated. A glsK deletion strain showed impaired growth with L-glutamine as carbon and energy source, while growth was improved upon glsK overexpression. GlsK possesses a carboxy-terminal domain that seems to be restricted to Corynebacterium species. A truncated GlsK lacking this extension led to faster growth, indicating a regulatory function of this domain. In fact, GlsK activity is regulated in a pH-dependent manner depending on the carboxy-terminal extension, and is positively influenced by cAMP. Furthermore, the C-terminal extension seems to be important for oligomerization of GlsK.
谷氨酸棒杆菌能够代谢不同的氮源和碳源。在标准基本培养基中,铵和尿素通常作为氮源,葡萄糖或蔗糖作为碳源和能源;然而,氨基酸也可能作为氮源、碳源和能源发挥作用。在本研究中,对假定的谷氨酰胺酶GlsK的功能进行了研究。一个glsK缺失菌株以L-谷氨酰胺作为碳源和能源时生长受损,而glsK过表达时生长得到改善。GlsK拥有一个羧基末端结构域,该结构域似乎仅限于棒杆菌属物种。一个缺少该延伸部分的截短GlsK导致生长更快,表明该结构域具有调节功能。事实上,GlsK的活性根据羧基末端延伸部分以pH依赖的方式受到调节,并受到cAMP的正向影响。此外,C末端延伸部分似乎对GlsK的寡聚化很重要。