Structure of a closed-form uroporphyrinogen-III C-methyltransferase from Thermus thermophilus.
Structure of a closed-form uroporphyrinogen-III C-methyltransferase from Thermus thermophilus.
复制标题
来自嗜热栖热菌的封闭式尿卟啉原-III C-甲基转移酶的结构。
DOI：
10.1107/s0907444905008838
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发表时间：
2005
期刊：
影响因子：
--
通讯作者：
T. Tahirov
中科院分区：
文献类型：
--
作者：
P. Rehse;Tomoe Kitao;T. Tahirov
来自嗜热热菌的尿卟啉原- iii c -甲基转移酶是一种多功能蛋白，在维生素B（12）合成过程中，负责8个依赖s -腺苷-蛋氨酸的corrin环甲基化中的2个。该蛋白的结构在载脂蛋白和辅因子结合形式下已被求解到2.0 A分辨率。单体由两个结构域A和B组成，每个结构域由一个五链β -片和两个或三个α -螺旋组成，辅因子结合在界面上。生物单元是在不对称单元中发现的二聚体。这种二聚体是由非结晶的双重结构连接起来的，这样两个B结构域结合形成一个长十链的β -片。与已解决的相关结构相比，该结构在参与辅因子和底物结合的区域显示出明显的差异，证实了先前涉及的几个残基的作用，并质疑其他残基。所解的相关结构的特征是有一个暴露的活性位点。嗜热T.嗜热菌结构的这个位点受一个高度保守残基的柔性环结构的相互作用限制，这表明这是一个机制作用。这个结构代表；封闭形式的蛋白质。
Uroporphyrinogen-III C-methyltransferase from Thermus thermophilus is a multifunctional protein responsible for two of the eight S-adenosyl-methionine-dependent methylations of the corrin ring during vitamin B(12) synthesis. The structure of this protein has been solved to 2.0 A resolution in both the apo and cofactor-bound form. The monomer consists of two domains, A and B, each consisting of a five-stranded beta-sheet and two or three alpha-helices, with the cofactor bound at the interface. The biological unit is the dimer found in the asymmetric unit. This dimer is related by a non-crystallographic twofold such that two B domains combine to form a long ten-stranded beta-sheet. When compared with solved related structures, this structure shows clear differences in the region involved in cofactor and substrate binding, affirming the role of several previously implicated residues and questioning others. The solved related structures are characterized by an exposed active site. The T. thermophilus structure has this site restricted by the interaction of a flexible loop structure with a highly conserved residue, suggesting a mechanistic role. This structure represents the ;closed' form of the protein.
影响因子：
5.6
作者：
J. Vévodová;R. Graham;E. Raux;H. Schubert;D. Roper;A. Brindley;A. Ian Scott;C. Roessner;N. Stamford;M. Elizabeth Stroupe;E. Getzoff;M. Warren;K. Wilson
通讯作者：
J. Vévodová;R. Graham;E. Raux;H. Schubert;D. Roper;A. Brindley;A. Ian Scott;C. Roessner;N. Stamford;M. Elizabeth Stroupe;E. Getzoff;M. Warren;K. Wilson