来自Lactobacillus curiae的与GCN5相关的N-乙转移酶的晶体结构
Jennifer R Fleming1, Franziskus Hauth2, Jörg S Hartig2
1Department of Biology, University of Konstanz, Universitätsstrasse 10, 78457 Konstanz, Germany.
概括
研究人员确定了Lactobacillus curiae guanidine riboswitch相关的N-乙转移酶 (LcGNAT) 的晶体结构. 这种酶乙化canavanine,揭示了GNAT蛋白家族的洞察力.
科学领域:
- 生物化学 生物化学
- 结构生物学 结构生物学
- 酶学 是一种酶学.
背景情况:
- 与GCN5相关的N-乙转移酶 (GNAT) 超级家族在生命中至关重要,参与各种细胞过程.
- 由于不同的宏分子标,GNATs表现出显著的多样性,但仍然在结构上缺乏特征.
- 了解GNAT结构-功能关系对于阐明它们在生物通路中的作用至关重要.
研究的目的:
- 为了确定 Lactobacillus curiae guanidine riboswitch相关的 N-乙转移酶 (LcGNAT) 的晶体结构.
- 描述LcGNAT的结构特征及其催化机制.
- 提供对不太了解的GNAT蛋白家族的结构洞察力.
主要方法:
- 采用X射线晶体学,获得LcGNAT.的3D结构.
- 进行了序列同质性分析,将LcGNAT与其他GNAT家族成员进行比较.
- 用局部定向突变发生法来研究特定残留物在催化中的作用.
主要成果:
- 确定了LcGNAT的晶体结构,LcGNAT是一种乙化阿尔金因类型卡纳瓦宁的酶.
- LcGNAT表现出保存的GNAT折叠,但缺乏N端β0链,并且具有退化的P环.
- 突变性发现Tyr142,Tyr97和Glu92对于LcGNAT的催化活性至关重要.
结论:
- LcGNAT与聚胺乙转移酶具有相同的结构特征,这表明了子类特定的适应性.
- 尽管具有独特的基质特异性,但LcGNAT可能采用了正规的GNAT反应机制.
- 这项研究增强了对多样化的GNAT超级家族的结构理解.
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