Histone acetyltransferase (Hpa2) is an unusual acetyltransferase, with a wide range of substrates; including histones, polyamines and aminoglycosides antibiotic. Hpa2 belongs to GNAT superfamily and GNATs are well known for the formation of homo-oligomers. However, the reason behind their oligomerization remained unexplored. Here, oligomeric states of Hpa2 were explored, to understand the functional significance of oligomerization. Biochemical analysis suggests that Hpa2 exists as dimer in solution and self-assembles into tetramer in the spermine, spermidine and kanamycin bound form. Stability analysis with denaturants concludes that homo-oligomerization of Hpa2 relies on bound substrate and not on experimental conditions. Homo-oligomerization in Hpa2 depicts direct correlation with its polyamine acetylating capacity. This correlation and in silico model structures suggest that oligomerization of Hpa2 is associated with the hastening of acetylation process. Interestingly, polyamine acetylation down regulates biofilms formation in E. coli BL21/Hpa2-transformants cells. Therefore, we propose that Hpa2 manipulates survival strategies of the bacterium via polyamines and antibiotics acetylation.

中文翻译：

---

多药耐药鲍曼不动杆菌的组蛋白乙酰转移酶中的多胺乙酰化和底物诱导的寡聚状态。

组蛋白乙酰基转移酶（Hpa2）是一种不常见的乙酰基转移酶，具有多种底物。包括组蛋白，多胺和氨基糖苷类抗生素。Hpa2属于GNAT超家族，GNAT以同源寡聚体的形成而闻名。然而，其低聚背后的原因仍待探索。在这里，探索Hpa2的寡聚状态，以了解寡聚化的功能意义。生化分析表明，Hpa2以二聚体形式存在于溶液中，并以精胺，亚精胺和卡那霉素的结合形式自组装成四聚体。用变性剂进行的稳定性分析得出结论，Hpa2的均聚取决于结合的底物，而不取决于实验条件。Hpa2中的均聚低聚反应与其多胺乙酰化能力直接相关。这种相关性和计算机模型结构表明，Hpa2的寡聚与乙酰化过程的加快有关。有趣的是，多胺乙酰化作用下调了大肠杆菌BL21 / Hpa2-转化子细胞中生物膜的形成。因此，我们建议Hpa2通过多胺和抗生素乙酰化来操纵细菌的生存策略。