Department of Biological Chemistry, Faculty of Agriculture, Yamaguchi University, Japan.
Biochem Biophys Res Commun. 2011 May 27;409(1):120-4. doi: 10.1016/j.bbrc.2011.04.126. Epub 2011 Apr 30.
Thermotolerant acetic acid bacteria (AAB), Acetobacter tropicalis SKU1100, can grow above 40°C. To investigate the basis of its thermotolerance, we compared the genome of A. tropicalis SKU1100 with that of mesophilic AAB strain Acetobacter pasteurianus IFO3283-01. The comparative genomic study showed that amino acid substitutions from large to small residue and Lys to Arg occur in many orthologous genes. Furthermore, comparative modeling study was carried out with the orthologous proteins between SKU1100 and IFO3283-01 strains, indicating that the number of Arg-based salt bridges increased in protein models. Since it has been reported that Arg-based salt bridges are important factor for thermo-stability of protein structure, our results strongly suggest that the increased number of Arg-based salt bridges may contributes to the thermotolerance of A. tropicalis SKU1100 (the thermo-stability of proteins in A. tropicalis SKU1100).
耐热醋酸菌（AAB），热带醋酸杆菌 SKU1100，可以在 40°C 以上生长。为了研究其耐热性的基础，我们比较了热带醋酸杆菌 SKU1100 的基因组与嗜温性 AAB 菌株巴氏醋酸杆菌IFO3283-01 的基因组。比较基因组研究表明，许多直系同源基因发生了从大到小残基和赖氨酸到精氨酸的氨基酸取代。此外，还对 SKU1100 和 IFO3283-01 菌株之间的直系同源蛋白进行了比较建模研究，表明蛋白模型中基于精氨酸的盐桥数量增加。由于已经报道了基于精氨酸的盐桥是蛋白质结构热稳定性的重要因素，我们的结果强烈表明，基于精氨酸的盐桥数量的增加可能有助于热带醋酸杆菌 SKU1100 的耐热性（热带醋酸杆菌 SKU1100 中蛋白质的热稳定性）。
