Arnaouteli Sofia, Giastas Petros, Andreou Athina, Tzanodaskalaki Mary, Aldridge Christine, Tzartos Socrates J, Vollmer Waldemar, Eliopoulos Elias, Bouriotis Vassilis
From the Department of Biology, Enzyme Biotechnology Group, University of Crete, Vasilika Vouton, 70013 Heraklion, Crete, Greece.
the Department of Neurobiology, Hellenic Pasteur Institute, Vasilissis Sofias 127, 11521 Athens, Greece.
J Biol Chem. 2015 May 22;290(21):13465-78. doi: 10.1074/jbc.M115.640029. Epub 2015 Mar 30.
Membrane-anchored lipoproteins have a broad range of functions and play key roles in several cellular processes in Gram-positive bacteria. BA0330 and BA0331 are the only lipoproteins among the 11 known or putative polysaccharide deacetylases of Bacillus anthracis. We found that both lipoproteins exhibit unique characteristics. BA0330 and BA0331 interact with peptidoglycan, and BA0330 is important for the adaptation of the bacterium to grow in the presence of a high concentration of salt, whereas BA0331 contributes to the maintenance of a uniform cell shape. They appear not to alter the peptidoglycan structure and do not contribute to lysozyme resistance. The high resolution x-ray structure of BA0330 revealed a C-terminal domain with the typical fold of a carbohydrate esterase 4 and an N-terminal domain unique for this family, composed of a two-layered (4 + 3) β-sandwich with structural similarity to fibronectin type 3 domains. Our data suggest that BA0330 and BA0331 have a structural role in stabilizing the cell wall of B. anthracis.
膜锚定脂蛋白具有广泛的功能，在革兰氏阳性菌的多个细胞过程中发挥关键作用。BA0330和BA0331是炭疽芽孢杆菌11种已知或推定的多糖脱乙酰酶中仅有的脂蛋白。我们发现这两种脂蛋白都具有独特的特性。BA0330和BA0331与肽聚糖相互作用，BA0330对于细菌在高浓度盐存在下生长的适应性很重要，而BA0331有助于维持均匀的细胞形态。它们似乎不会改变肽聚糖结构，也不会增强对溶菌酶的抗性。BA0330的高分辨率x射线结构显示，其C端结构域具有典型的碳水化合物酯酶4折叠，N端结构域为此家族所特有，由两层（4 + 3）β折叠片层组成，与纤连蛋白3型结构域具有结构相似性。我们的数据表明，BA0330和BA0331在稳定炭疽芽孢杆菌细胞壁方面具有结构作用。
