Liu Wen-Juan, Dong Hao, Peng Xiao-Wei, Wu Qing-Min
Key Laboratory of Animal Epidemiology and Zoonosis of Ministry of Agriculture, College of Veterinary Medicine, China Agricultural University, Beijing, China.
FEMS Microbiol Lett. 2014 Jul;356(1):79-88. doi: 10.1111/1574-6968.12472. Epub 2014 Jun 26.
Brucella melitensis possesses an operon with two components: the response regulator OtpR and a putative cAMP-dependent protein kinase regulatory subunit encoded by the BMEI0067 gene. In the previous study, the function of OtpR has been studied, while little is known about the function of the BMEI0067 gene. Using a bioinformatics approach, we showed that the BMEI0067 gene encodes an additional putative cAMP-binding protein, which we refer to as CbpB. Structural modeling predicted that CbpB has a cAMP-binding protein (CAP) domain and is structurally similar to eukaryotic protein kinase A regulatory subunits. Here, we report the characterization of CbpB, a cAMP-binding protein in Brucella melitensis, showed to be involved in mouse persistent infections. ∆cbpB::km possessed cell elongation, bubble-like protrusions on cell surface and its resistance to environmental stresses (temperature, osmotic stress and detergent). Interestingly, comparative real-time qPCR assays, the cbpB mutation resulted in significantly different expression of aqpX and several penicillin-binding proteins and cell division proteins in Brucella. Combined, these results demonstrated characterization of CbpB in B. melitensis and its key role for intracellular multiplication.
应答调节因子OtpR和由BMEI0067基因编码的假定的cAMP依赖性蛋白激酶调节亚基。在先前的研究中，已经对OtpR的功能进行了研究，而关于BMEI0067基因的功能却知之甚少。我们采用生物信息学方法表明，BMEI0067基因编码另一种假定的cAMP结合蛋白，我们将其称为CbpB。结构建模预测，CbpB具有一个cAMP结合蛋白（CAP）结构域，并且在结构上与真核蛋白激酶A调节亚基相似。在此，我们报告了羊种布鲁氏菌中一种参与小鼠持续感染的cAMP结合蛋白CbpB的特性。∆cbpB::km具有细胞伸长、细胞表面出现泡状突起以及对环境压力（温度、渗透压和去污剂）的抗性。有趣的是，通过比较实时定量PCR分析，cbpB突变导致布鲁氏菌中aqpX以及几种青霉素结合蛋白和细胞分裂蛋白的表达存在显著差异。综合这些结果表明了羊种布鲁氏菌中CbpB的特性及其在细胞内增殖中的关键作用。
