Structure and properties of a bis-histidyl ligated globin from Caenorhabditis elegans.
Structure and properties of a bis-histidyl ligated globin from Caenorhabditis elegans.
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DOI：
10.1021/bi100710a
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发表时间：
2010-07-13
期刊：
影响因子：
2.9
通讯作者：
Marletta MA
中科院分区：
文献类型：
--
作者：
Yoon J;Herzik MA Jr;Winter MB;Tran R;Olea C Jr;Marletta MA
珠蛋白是一种含血红素的蛋白质，以其在氧气运输和储存中的作用而闻名。然而，球蛋白在生物学中的作用越来越多，包括气体和氧化还原传感。在秀丽隐杆线虫中，最近已经鉴定出33个珠蛋白或珠蛋白样基因，其中一些已知在蠕虫的感觉神经元中表达，并与O2感知行为有关。在这里，我们描述了GLB-6，一种在秀丽隐杆线虫神经元中表达的新型珠蛋白样蛋白。重组表达的全长GLB-6包含一个血红素位点，其光谱特征与其他双组氨酸连接的珠蛋白（如神经珠蛋白和细胞珠蛋白）相似。然而，与这些球蛋白相反，在GLB-6中，CO、NO和CN -等配体不与血红素结合，这表明内源性组氨酸配体可能是非常紧密协调的。此外，GLB-6在生理氧水平和低氧化还原电位（- 193±2 mV）存在下表现出快速的两态自氧化动力学。GLB-6血红素结构域的高分辨率（1.40 Å）晶体结构证实了假定的球蛋白折叠和双组氨酸连接，并证明了与全长蛋白所表现出的不寻常的配体结合和氧化还原特性相关的关键结构特征。综上所述，GLB-6的生化特性表明，这种神经蛋白很可能通过氧化还原信号和/或电子转移在秀丽隐杆线虫中充当O2的生理传感器。
Globins are heme-containing proteins that are best known for their roles in oxygen (O2) transport and storage. However, more diverse roles of globins in biology are being revealed, including gas and redox sensing. In the nematode Caenorhabditis elegans, 33 globin or globin-like genes have been recently identified, some of which are known to be expressed in the sensory neurons of the worm and linked to O2 sensing behavior. Here, we describe GLB-6, a novel globin-like protein expressed in the neurons of C. elegans. Recombinantly expressed full-length GLB-6 contains a heme site with spectral features that are similar to those of other bis-histidyl ligated globins, such as neuroglobin and cytoglobin. In contrast to these globins, however, ligands such as CO, NO, and CN− do not bind to the heme in GLB-6, demonstrating that the endogenous histidine ligands are likely very tightly coordinated. Additionally, GLB-6 exhibits rapid two-state autoxidation kinetics in the presence of physiological O2 levels as well as a low redox potential (−193 ± 2 mV). A high resolution (1.40 Å) crystal structure of the ferric form of the heme-domain of GLB-6 confirms both the putative globin-fold and bis-histidyl ligation and also demonstrates key structural features that can be correlated with the unusual ligand binding and redox properties exhibited by the full-length protein. Taken together, the biochemical properties of GLB-6 suggest that this neural protein would most likely serve as a physiological sensor for O2 in C. elegans via redox signaling and/or electron transfer.
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影响因子：
9.8
作者：
Chang AJ;Chronis N;Karow DS;Marletta MA;Bargmann CI
通讯作者：
Bargmann CI
DOI：
10.1073/pnas.95.18.10378
发表时间：
1998-09-01
影响因子：
11.1
作者：
Gardner, PR;Gardner, AM;Salzman, AL
通讯作者：
Salzman, AL
DOI：
10.1107/s0907444904019158
发表时间：
2004-12-01
影响因子：
2.2
作者：
Emsley, P;Cowtan, K
通讯作者：
Cowtan, K
影响因子：
64.8
作者：
Hou, SB;Larsen, RW;Alam, M
通讯作者：
Alam, M
影响因子：
4.8
作者：
DOU, Y;ADMIRAAL, SJ;GEORGE, GN
通讯作者：
GEORGE, GN