Department of Life Science, University of Seoul, Seoul 130-743, Republic of Korea.
Biochem Biophys Res Commun. 2011 Jun 24;410(1):52-6. doi: 10.1016/j.bbrc.2011.05.103. Epub 2011 May 24.
PA2196 of Pseudomonas aeruginosa is a putative transcriptional regulator and belongs to the TetR family repressor that is involved in adaptations to environmental changes and bacterial antibiotic resistance. The crystal structure of PA2196 determined to 2.4Å resolution revealed nine α-helical bundles that can be divided into N-terminal DNA binding domain with an α-helix-turn-α-helix motif and C-terminal ligand binding domain with a hydrophobic ligand binding pocket. The distance between the N-terminal domains of homodimeric PA2196 suggested that our structure is similar to the DNA-bound form of other TetR family proteins. The C-terminal ligand binding pocket is composed mainly of hydrophobic residues and has a volume of about 523Å(3) with two openings. PA2196 binds to the upstream region and can regulate the downstream genes that are chemical modification enzymes. Our crystal structure of PA2196 provides insights about the DNA recognition and ligand binding characteristics.
铜绿假单胞菌 PA2196 是一个假定的转录调控因子，属于 TetR 家族阻遏物，参与环境变化和细菌抗生素耐药性的适应。测定到 2.4Å 分辨率的 PA2196 晶体结构揭示了九个α-螺旋束，可以分为具有α-螺旋-转角-α-螺旋基序的 N-端 DNA 结合域和具有疏水性配体结合口袋的 C-端配体结合域。同源二聚体 PA2196 的 N-端结构域之间的距离表明我们的结构类似于其他 TetR 家族蛋白的 DNA 结合形式。C-端配体结合口袋主要由疏水性残基组成，体积约为 523Å(3)，有两个开口。PA2196 结合在上游区域，可调节化学修饰酶的下游基因。我们的 PA2196 晶体结构提供了有关 DNA 识别和配体结合特性的见解。
