The crystal structure of Escherichia coli heat shock protein YedU reveals three potential catalytic active sites.
The crystal structure of Escherichia coli heat shock protein YedU reveals three potential catalytic active sites.
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大肠杆菌热休克蛋白 YedU 的晶体结构揭示了三个潜在的催化活性位点。
DOI：
10.1110/ps.03121403
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发表时间：
2003
期刊：
影响因子：
--
通讯作者：
Fox,RobertO
中科院分区：
文献类型：
--
作者：
Zhao,Yonghong;Liu,Deqian;Kaluarachchi,WarnaD;Bellamy,HenryD;White,MarkA;Fox,RobertO
大肠杆菌yedU基因的mRNA在热休克时被诱导31倍。31 kD的YedU蛋白，也称为Hsp 31，在几种人类病原体中高度保守，并具有伴侣活性。我们以2.2 μ m的分辨率解出了YedU的晶体结构。YedU单体具有α/β/α夹心结构域和小的α/β结构域。YedU在溶液中是二聚体，其晶体结构表明在二聚化时掩埋了大量的表面积。存在穿过蛋白质表面上的二聚体界面的延伸的疏水补丁。这种疏水斑块可能是负责分子伴侣活性的底物结合位点。该结构还揭示了由Cys 184，His 185和Asp 213组成的潜在蛋白酶样催化三联体，尽管没有鉴定出酶活性。YedU使用His 85、His 122和Glu 90配位金属离子。这种2-His-1-羧酸基序存在于羧肽酶A（一种锌酶）以及许多利用铁作为辅因子的双加氧酶和羟化酶中，这表明YedU的另一个潜在功能。
The mRNA ofEscherichia coli yedUgene is induced 31‐fold upon heat shock. The 31‐kD YedU protein, also calls Hsp31, is highly conserved in several human pathogens and has chaperone activity. We solved the crystal structure of YedU at 2.2 Å resolution. YedU monomer has an α/β/α sandwich domain and a small α/β domain. YedU is a dimer in solution, and its crystal structure indicates that a significant amount of surface area is buried upon dimerization. There is an extended hydrophobic patch that crosses the dimer interface on the surface of the protein. This hydrophobic patch is likely the substrate‐binding site responsible for the chaperone activity. The structure also reveals a potential protease‐like catalytic triad composed of Cys184, His185, and Asp213, although no enzymatic activity could be identified. YedU coordinates a metal ion using His85, His122, and Glu90. This 2‐His‐1‐carboxylate motif is present in carboxypeptidase A (a zinc enzyme), and a number of dioxygenases and hydroxylases that utilize iron as a cofactor, suggesting another potential function for YedU.