Abstract：
Streptococcus pneumoniae is a leading cause of community-acquired pneumonia and is responsible for acute invasive and non-invasive infections. Fight against pneumococcus is currently hampered by insufficient vaccine coverage and rising antimicrobial resistance, making the research necessary on novel drug targets. High-throughput mutagenesis has shown that acetyl-CoA carboxylase (ACC) is an essential enzyme in S. pneumoniae which converts acetyl-CoA to malonyl-CoA, a key step in fatty acid biosynthesis. ACC has four subunits; Biotin carboxyl carrier protein (BCCP), Biotin carboxylase (BC), Carboxyl transferase subunit α and β. Biotinylation of S. pneumoniae BCCP (SpBCCP) is required for the activation of ACC complex. In this study, we have biophysically characterized the apo- and holo- biotinylating domain SpBCCP80. We have performed 2D and 3D NMR experiments to analyze the changes in amino acid residues upon biotinylation of SpBCCP80. Further, we used NMR backbone chemical shift assignment data for bioinformatical analyses to determine the secondary and tertiary structure of proteins. We observed major changes in AMKVM motif and thumb region of SpBCCP80 upon biotinylation. Overall, this work provides structural insight into the apo- to holo- conversion of SpBCCP80 which can be further used as a drug target against S. pneumoniae.
摘要：
肺炎链球菌是社区获得性肺炎的主要原因，是急性侵入性和非侵入性感染的原因。目前，疫苗覆盖率不足和抗菌素耐药性上升阻碍了与肺炎球菌的斗争。使新药靶点的研究成为必要。高通量诱变表明，乙酰辅酶A羧化酶（ACC）是肺炎链球菌中的必需酶，可将乙酰辅酶A转化为丙二酰辅酶A，脂肪酸生物合成的关键步骤。ACC有四个亚基；生物素羧基载体蛋白（BCCP），生物素羧化酶(BC),羧基转移酶亚基α和β。激活ACC复合物需要肺炎链球菌BCCP(SpBCCP)的生物素化。在这项研究中,我们已经对SpBCCP80的apo-和全-生物素化结构域进行了生物物理表征。我们进行了2D和3DNMR实验，以分析SpBCCP80生物素化后氨基酸残基的变化。Further,我们使用NMR主链化学位移分配数据进行生物信息学分析，以确定蛋白质的二级和三级结构。我们观察到生物素化后AMKVM基序和SpBCCP80拇指区的主要变化。总的来说,这项工作提供了对SpBCCP80的全转换的结构见解,SpBCCP80可进一步用作抗肺炎链球菌的药物靶标.
